diff --git a/includes/Checker/Abstract_Check_Runner.php b/includes/Checker/Abstract_Check_Runner.php
index b1762344a..b09d27a86 100644
--- a/includes/Checker/Abstract_Check_Runner.php
+++ b/includes/Checker/Abstract_Check_Runner.php
@@ -55,7 +55,17 @@ abstract protected function get_check_slugs_to_run();
 	public function prepare() {
 		if ( $this->requires_universal_preparations( $this->get_checks_to_run() ) ) {
 			$preparation = new Universal_Runtime_Preparation( $this->get_checks_instance()->context() );
-			return $preparation->prepare();
+			$cleanup     = $preparation->prepare();
+
+			// Set the database prefix to use the demo tables.
+			global $wpdb;
+			$old_prefix = $wpdb->set_prefix( 'wppc_' );
+
+			return function() use ( $old_prefix, $cleanup ) {
+				global $wpdb;
+				$wpdb->set_prefix( $old_prefix );
+				$cleanup();
+			};
 		}
 
 		return function() {};
diff --git a/includes/Checker/Runtime_Environment_Setup.php b/includes/Checker/Runtime_Environment_Setup.php
new file mode 100644
index 000000000..78acb4dc1
--- /dev/null
+++ b/includes/Checker/Runtime_Environment_Setup.php
@@ -0,0 +1,97 @@
+<?php
+/**
+ * Class WordPress\Plugin_Check\Checker\Runtime_Environment_Setup
+ *
+ * @package plugin-check
+ */
+
+namespace WordPress\Plugin_Check\Checker;
+
+/**
+ * Class to setup the Runtime Environment for Runtime checks.
+ *
+ * @since n.e.x.t
+ */
+class Runtime_Environment_Setup {
+
+	/**
+	 * Sets up the WordPress environment for runtime checks
+	 *
+	 * @since n.e.x.t
+	 */
+	public function setup() {
+		global $wpdb, $wp_filesystem;
+
+		require_once ABSPATH . '/wp-admin/includes/upgrade.php';
+
+		// Set the new prefix.
+		$old_prefix = $wpdb->set_prefix( 'wppc_' );
+
+		// Create and populate the test database tables if they do not exist.
+		if ( 'wppc_posts' !== $wpdb->get_var( "SHOW TABLES LIKE 'wppc_posts'" ) ) {
+			wp_install(
+				'Plugin Check',
+				'plugincheck',
+				'demo@plugincheck.test',
+				false
+			);
+		}
+
+		// Restore the old prefix.
+		$wpdb->set_prefix( $old_prefix );
+
+		// Return early if the plugin check object cache already exists.
+		if ( defined( 'WP_PLUGIN_CHECK_OBJECT_CACHE_DROPIN_VERSION' ) && WP_PLUGIN_CHECK_OBJECT_CACHE_DROPIN_VERSION ) {
+			return;
+		}
+
+		// Create the object-cache.php file.
+		if ( $wp_filesystem || WP_Filesystem() ) {
+			// Do not replace the object-cache.php file if it already exists.
+			if ( ! $wp_filesystem->exists( WP_CONTENT_DIR . '/object-cache.php' ) ) {
+				$wp_filesystem->copy( WP_PLUGIN_CHECK_PLUGIN_DIR_PATH . 'object-cache.copy.php', WP_CONTENT_DIR . '/object-cache.php' );
+			}
+		}
+	}
+
+	/**
+	 * Cleans up the runtime environment setup.
+	 *
+	 * @since n.e.x.t
+	 */
+	public function cleanup() {
+		global $wpdb, $wp_filesystem;
+
+		require_once ABSPATH . '/wp-admin/includes/upgrade.php';
+
+		$old_prefix = $wpdb->set_prefix( 'wppc_' );
+		$tables     = $wpdb->tables();
+
+		foreach ( $tables as $table ) {
+			$wpdb->query( "DROP TABLE IF EXISTS `$table`" ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
+		}
+
+		// Restore the old prefix.
+		$wpdb->set_prefix( $old_prefix );
+
+		// Return early if the plugin check object cache does not exist.
+		if ( ! defined( 'WP_PLUGIN_CHECK_OBJECT_CACHE_DROPIN_VERSION' ) || ! WP_PLUGIN_CHECK_OBJECT_CACHE_DROPIN_VERSION ) {
+			return;
+		}
+
+		// Remove the object-cache.php file.
+		if ( $wp_filesystem || WP_Filesystem() ) {
+			if ( ! $wp_filesystem->exists( WP_CONTENT_DIR . '/object-cache.php' ) ) {
+				return;
+			}
+
+			// Check the drop-in file matches the copy.
+			$original_content = $wp_filesystem->get_contents( WP_CONTENT_DIR . '/object-cache.php' );
+			$copy_content     = $wp_filesystem->get_contents( WP_PLUGIN_CHECK_PLUGIN_DIR_PATH . 'object-cache.copy.php' );
+
+			if ( $original_content && $original_content === $copy_content ) {
+				$wp_filesystem->delete( WP_CONTENT_DIR . '/object-cache.php' );
+			}
+		}
+	}
+}
diff --git a/includes/Utilities/Plugin_Request_Utility.php b/includes/Utilities/Plugin_Request_Utility.php
index e06162ba4..10c9b5721 100644
--- a/includes/Utilities/Plugin_Request_Utility.php
+++ b/includes/Utilities/Plugin_Request_Utility.php
@@ -8,6 +8,8 @@
 namespace WordPress\Plugin_Check\Utilities;
 
 use Exception;
+use WordPress\Plugin_Check\Checker\CLI_Runner;
+use WordPress\Plugin_Check\Checker\AJAX_Runner;
 
 /**
  * Class providing utility methods to return plugin information based on the request.
@@ -16,6 +18,22 @@
  */
 class Plugin_Request_Utility {
 
+	/**
+	 * Instance of the current runner based on the request.
+	 *
+	 * @since n.e.x.t
+	 * @var Abstract_Check_Runner
+	 */
+	protected static $runner;
+
+	/**
+	 * The universal runtime preparation cleanups if applied.
+	 *
+	 * @since n.e.x.t
+	 * @var callable
+	 */
+	protected static $cleanup;
+
 	/**
 	 * Returns the plugin basename based on the input provided.
 	 *
@@ -60,4 +78,40 @@ public static function get_plugin_basename_from_input( $plugin_slug ) {
 			)
 		);
 	}
+
+	/**
+	 * Initializes the runner classes.
+	 *
+	 * @since n.e.x.t
+	 */
+	public static function initialize_runner() {
+		$runners = array(
+			new CLI_Runner(),
+			new AJAX_Runner(),
+		);
+
+		foreach ( $runners as $runner ) {
+			if ( $runner->is_plugin_check() ) {
+				// @TODO: Handle the cleanup function in later issue with shutdown action or method that returns cleanup functions.
+				static::$cleanup = $runner->prepare();
+				static::$runner  = $runner;
+				break;
+			}
+		}
+	}
+
+	/**
+	 * Get the Runner class for the current request.
+	 *
+	 * @since n.e.x.t
+	 *
+	 * @return Abstract_Check_Runner|null The Runner class for the request or null.
+	 */
+	public static function get_runner() {
+		if ( isset( static::$runner ) ) {
+			return static::$runner;
+		}
+
+		return null;
+	}
 }
diff --git a/object-cache.copy.php b/object-cache.copy.php
new file mode 100644
index 000000000..3684c7b1e
--- /dev/null
+++ b/object-cache.copy.php
@@ -0,0 +1,43 @@
+
+<?php
+/**
+ * Plugin Name: Plugin Check Object Cache Drop-In
+ * Plugin URI: https://github.com/WordPress/plugin-check
+ * Description: Plugin check drop-in to setup the test environment early. This is not a real object cache drop-in and will not override other actual object cache drop-ins.
+ * Version: 1
+ * Author: WordPress Performance Team
+ * Author URI: https://make.wordpress.org/performance/
+ * License: GPLv2 or later
+ * License URI: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+ *
+ * Object cache drop-in from Plugin Check.
+ *
+ * This drop-in is used, admittedly as a hack, to be able to setup the
+ * WordPress environment as early as possible. Once a plugin is loaded, it is
+ * too late to configure the test environment.
+ *
+ * This file respects any real object cache implementation the site may already
+ * be using, and it is implemented in a way that there is no risk for breakage.
+ *
+ * @package plugin-check
+ * @since n.e.x.t
+ */
+
+// Set constant to be able to later check for whether this file was loaded.
+define( 'WP_PLUGIN_CHECK_OBJECT_CACHE_DROPIN_VERSION', 1 );
+
+function plugin_check_initialize_runner() {
+	$plugins_dir = defined( 'WP_PLUGIN_DIR' ) ? WP_PLUGIN_DIR : WP_CONTENT_DIR . '/plugins';
+	$plugin_dir  = $plugins_dir . '/plugin-check/';
+	if ( ! file_exists( $plugin_dir . 'vendor/autoload.php' ) ) {
+		return;
+	}
+
+	require_once $plugin_dir . 'vendor/autoload.php';
+
+	if ( class_exists( 'WordPress\Plugin_Check\Utilities\Plugin_Request_Utility' ) ) {
+		// Initialize the Check Runner class based on the request.
+		WordPress\Plugin_Check\Utilities\Plugin_Request_Utility::initialize_runner();
+	}
+}
+plugin_check_initialize_runner();
diff --git a/tests/Checker/AJAX_Runner_Tests.php b/tests/Checker/AJAX_Runner_Tests.php
index 52a4160c3..c3c82ac7a 100644
--- a/tests/Checker/AJAX_Runner_Tests.php
+++ b/tests/Checker/AJAX_Runner_Tests.php
@@ -10,6 +10,13 @@
 
 class AJAX_Runner_Tests extends WP_UnitTestCase {
 
+	public function tear_down() {
+		// Force reset the database prefix after runner prepare method called.
+		global $wpdb, $table_prefix;
+		$wpdb->set_prefix( $table_prefix );
+		parent::tear_down();
+	}
+
 	public function test_is_plugin_check_returns_true() {
 		// Mock the AJAX request.
 		add_filter( 'wp_doing_ajax', '__return_true' );
diff --git a/tests/Checker/CLI_Runner_Tests.php b/tests/Checker/CLI_Runner_Tests.php
index 278f3f211..4b416ac16 100644
--- a/tests/Checker/CLI_Runner_Tests.php
+++ b/tests/Checker/CLI_Runner_Tests.php
@@ -10,6 +10,13 @@
 
 class CLI_Runner_Tests extends WP_UnitTestCase {
 
+	public function tear_down() {
+		// Force reset the database prefix after runner prepare method called.
+		global $wpdb, $table_prefix;
+		$wpdb->set_prefix( $table_prefix );
+		parent::tear_down();
+	}
+
 	public function test_is_plugin_check_returns_true() {
 		$_SERVER['argv'] = array(
 			'wp',
diff --git a/tests/Checker/Runtime_Environment_Setup_Tests.php b/tests/Checker/Runtime_Environment_Setup_Tests.php
new file mode 100644
index 000000000..7f44fddc3
--- /dev/null
+++ b/tests/Checker/Runtime_Environment_Setup_Tests.php
@@ -0,0 +1,98 @@
+<?php
+/**
+ * Tests for the Checks class.
+ *
+ * @package plugin-check
+ */
+
+use WordPress\Plugin_Check\Checker\Runtime_Environment_Setup;
+
+class Runtime_Environment_Setup_Tests extends WP_UnitTestCase {
+
+	public function test_setup() {
+		global $wp_filesystem, $wpdb;
+
+		$this->set_up_mock_filesystem();
+
+		$runtime_setup = new Runtime_Environment_Setup();
+		$runtime_setup->setup();
+
+		$this->assertTrue( 0 <= strpos( $wpdb->last_query, 'wppc_' ) );
+		$this->assertTrue( $wp_filesystem->exists( WP_CONTENT_DIR . '/object-cache.php' ) );
+		$this->assertSame( file_get_contents( WP_PLUGIN_CHECK_PLUGIN_DIR_PATH . 'object-cache.copy.php' ), $wp_filesystem->get_contents( WP_CONTENT_DIR . '/object-cache.php' ) );
+	}
+
+	public function test_cleanup() {
+		global $wp_filesystem, $wpdb;
+
+		$this->set_up_mock_filesystem();
+
+		$runtime_setup = new Runtime_Environment_Setup();
+		$runtime_setup->setup();
+
+		// Simulate file exists by setting constant found in object-cache.php.
+		define( 'WP_PLUGIN_CHECK_OBJECT_CACHE_DROPIN_VERSION', 1 );
+
+		$runtime_setup->cleanup();
+
+		$this->assertTrue( 0 <= strpos( $wpdb->last_query, 'wppc_' ) );
+		$this->assertFalse( $wp_filesystem->exists( WP_CONTENT_DIR . '/object-cache.php' ) );
+	}
+
+	public function test_setup_with_existing_object_cache() {
+		global $wp_filesystem, $wpdb;
+
+		$this->set_up_mock_filesystem();
+
+		// Simulate a different object-cache.php.
+		$dummy_file_content = '<?php /* Empty object-cache.php drop-in file. */';
+		$wp_filesystem->put_contents( WP_CONTENT_DIR . '/object-cache.php', $dummy_file_content );
+
+		$runtime_setup = new Runtime_Environment_Setup();
+		$runtime_setup->setup();
+
+		$this->assertTrue( 0 <= strpos( $wpdb->last_query, 'wppc_' ) );
+		$this->assertTrue( $wp_filesystem->exists( WP_CONTENT_DIR . '/object-cache.php' ) );
+		$this->assertSame( $dummy_file_content, $wp_filesystem->get_contents( WP_CONTENT_DIR . '/object-cache.php' ) );
+	}
+
+	public function test_cleanup_with_existing_object_cache() {
+		global $wp_filesystem, $wpdb;
+
+		$this->set_up_mock_filesystem();
+
+		// Simulate a different object-cache.php.
+		$dummy_file_content = '<?php /* Empty object-cache.php drop-in file. */';
+		$wp_filesystem->put_contents( WP_CONTENT_DIR . '/object-cache.php', $dummy_file_content );
+
+		$runtime_setup = new Runtime_Environment_Setup();
+		$runtime_setup->setup();
+		$runtime_setup->cleanup();
+
+		$this->assertTrue( 0 <= strpos( $wpdb->last_query, 'wppc_' ) );
+		$this->assertTrue( $wp_filesystem->exists( WP_CONTENT_DIR . '/object-cache.php' ) );
+		$this->assertSame( $dummy_file_content, $wp_filesystem->get_contents( WP_CONTENT_DIR . '/object-cache.php' ) );
+	}
+
+	private function set_up_mock_filesystem() {
+		global $wp_filesystem;
+
+		add_filter(
+			'filesystem_method_file',
+			function() {
+				return __DIR__ . '/../testdata/Filesystem/WP_Filesystem_MockFilesystem.php';
+			}
+		);
+		add_filter(
+			'filesystem_method',
+			function() {
+				return 'MockFilesystem';
+			}
+		);
+
+		WP_Filesystem();
+
+		// Simulate that the original object-cache.copy.php file exists.
+		$wp_filesystem->put_contents( WP_PLUGIN_CHECK_PLUGIN_DIR_PATH . 'object-cache.copy.php', file_get_contents( WP_PLUGIN_CHECK_PLUGIN_DIR_PATH . 'object-cache.copy.php' ) );
+	}
+}
diff --git a/tests/Utilities/Plugin_Request_Utility_Tests.php b/tests/Utilities/Plugin_Request_Utility_Tests.php
index 47b677f57..a0ea70f0e 100644
--- a/tests/Utilities/Plugin_Request_Utility_Tests.php
+++ b/tests/Utilities/Plugin_Request_Utility_Tests.php
@@ -6,6 +6,8 @@
  */
 
 use WordPress\Plugin_Check\Utilities\Plugin_Request_Utility;
+use WordPress\Plugin_Check\Checker\CLI_Runner;
+use WordPress\Plugin_Check\Checker\AJAX_Runner;
 
 class Plugin_Request_Utility_Tests extends WP_UnitTestCase {
 
@@ -28,4 +30,31 @@ public function test_get_plugin_basename_from_input_with_invalid_input() {
 
 		Plugin_Request_Utility::get_plugin_basename_from_input( 'invalid' );
 	}
+
+	public function test_initialize_runner_with_cli() {
+		$_SERVER['argv'] = array(
+			'wp',
+			'plugin',
+			'check',
+			'plugin-check',
+		);
+
+		Plugin_Request_Utility::initialize_runner();
+		$runner = Plugin_Request_Utility::get_runner();
+
+		unset( $_SERVER['argv'] );
+
+		$this->assertInstanceOf( CLI_Runner::class, $runner );
+	}
+
+	public function test_initialize_runner_with_ajax() {
+		add_filter( 'wp_doing_ajax', '__return_true' );
+		$_REQUEST['action'] = 'plugin_check_run_checks';
+		$_REQUEST['plugin'] = 'plugin-check';
+
+		Plugin_Request_Utility::initialize_runner();
+		$runner = Plugin_Request_Utility::get_runner();
+
+		$this->assertInstanceOf( AJAX_Runner::class, $runner );
+	}
 }
diff --git a/tests/testdata/Filesystem/WP_Filesystem_MockFilesystem.php b/tests/testdata/Filesystem/WP_Filesystem_MockFilesystem.php
new file mode 100644
index 000000000..8729c2062
--- /dev/null
+++ b/tests/testdata/Filesystem/WP_Filesystem_MockFilesystem.php
@@ -0,0 +1,141 @@
+<?php
+/**
+ * This file needs to be in the global namespace due to how WordPress requires loading it.
+ *
+ * @package plugin-check
+ */
+
+require_once ABSPATH . '/wp-admin/includes/class-wp-filesystem-base.php';
+
+/**
+ * Simple mock filesystem, limited to working with concrete file paths.
+ * No support for hierarchy or parent directories etc.
+ *
+ * Could be expanded in the future if needed.
+ */
+class WP_Filesystem_MockFilesystem extends WP_Filesystem_Base {
+
+	private $file_contents = array();
+
+	public function get_contents( $file ) {
+		if ( isset( $this->file_contents[ $file ] ) ) {
+			return $this->file_contents[ $file ];
+		}
+		return false;
+	}
+
+	public function get_contents_array( $file ) {
+		if ( isset( $this->file_contents[ $file ] ) ) {
+			return array( $this->file_contents[ $file ] );
+		}
+		return false;
+	}
+
+	public function put_contents( $file, $contents, $mode = false ) {
+		$this->file_contents[ $file ] = $contents;
+		return true;
+	}
+
+	public function cwd() {
+		return false;
+	}
+
+	public function chdir( $dir ) {
+		return false;
+	}
+
+	public function chgrp( $file, $group, $recursive = false ) {
+		return false;
+	}
+
+	public function chmod( $file, $mode = false, $recursive = false ) {
+		return false;
+	}
+
+	public function owner( $file ) {
+		return false;
+	}
+
+	public function group( $file ) {
+		return false;
+	}
+
+	public function copy( $source, $destination, $overwrite = false, $mode = false ) {
+		if ( ! isset( $this->file_contents[ $source ] ) ) {
+			return false;
+		}
+		if ( ! $overwrite && isset( $this->file_contents[ $destination ] ) ) {
+			return false;
+		}
+		$this->file_contents[ $destination ] = $this->file_contents[ $source ];
+		return true;
+	}
+
+	public function move( $source, $destination, $overwrite = false ) {
+		if ( $this->copy( $source, $destination, $overwrite, false ) ) {
+			return $this->delete( $source );
+		}
+		return false;
+	}
+
+	public function delete( $file, $recursive = false, $type = false ) {
+		if ( isset( $this->file_contents[ $file ] ) ) {
+			unset( $this->file_contents[ $file ] );
+		}
+		return true;
+	}
+
+	public function exists( $path ) {
+		return isset( $this->file_contents[ $path ] );
+	}
+
+	public function is_file( $file ) {
+		return isset( $this->file_contents[ $file ] );
+	}
+
+	public function is_dir( $path ) {
+		return false;
+	}
+
+	public function is_readable( $file ) {
+		return isset( $this->file_contents[ $file ] );
+	}
+
+	public function is_writable( $path ) {
+		return true;
+	}
+
+	public function atime( $file ) {
+		return false;
+	}
+
+	public function mtime( $file ) {
+		return false;
+	}
+
+	public function size( $file ) {
+		if ( isset( $this->file_contents[ $file ] ) ) {
+			return strlen( $this->file_contents[ $file ] );
+		}
+		return false;
+	}
+
+	public function touch( $file, $time = 0, $atime = 0 ) {
+		if ( ! isset( $this->file_contents[ $file ] ) ) {
+			$this->file_contents[ $file ] = '';
+		}
+		return true;
+	}
+
+	public function mkdir( $path, $chmod = false, $chown = false, $chgrp = false ) {
+		return false;
+	}
+
+	public function rmdir( $path, $recursive = false ) {
+		return false;
+	}
+
+	public function dirlist( $path, $include_hidden = true, $recursive = false ) {
+		return false;
+	}
+}