diff --git a/components/server/ee/src/workspace/gitpod-server-impl.ts b/components/server/ee/src/workspace/gitpod-server-impl.ts
index 9ac2d9fe574f39..b9f57f19d0ca44 100644
--- a/components/server/ee/src/workspace/gitpod-server-impl.ts
+++ b/components/server/ee/src/workspace/gitpod-server-impl.ts
@@ -232,7 +232,10 @@ export class GitpodServerEEImpl extends GitpodServerImpl {
 
         const result = await this.eligibilityService.mayStartWorkspace(user, new Date(), runningInstances);
         if (!result.enoughCredits) {
-            throw new ResponseError(ErrorCodes.NOT_ENOUGH_CREDIT, `Not enough monthly workspace hours. Please upgrade your account to get more hours for your workspaces.`);
+            throw new ResponseError(
+                ErrorCodes.NOT_ENOUGH_CREDIT,
+                `Not enough monthly workspace hours. Please upgrade your account to get more hours for your workspaces.`,
+            );
         }
         if (!!result.hitParallelWorkspaceLimit) {
             throw new ResponseError(
@@ -565,14 +568,13 @@ export class GitpodServerEEImpl extends GitpodServerImpl {
 
         await this.guardAdminAccess("adminBlockUser", { req }, Permission.ADMIN_USERS);
 
-        const target = await this.userDB.findUserById(req.id);
-        if (!target) {
+        let targetUser;
+        try {
+            targetUser = await this.userService.blockUser(req.id, req.blocked);
+        } catch (error) {
             throw new ResponseError(ErrorCodes.NOT_FOUND, "not found");
         }
 
-        target.blocked = !!req.blocked;
-        await this.userDB.storeUser(target);
-
         const workspaceDb = this.workspaceDb.trace(ctx);
         const workspaces = await workspaceDb.findWorkspacesByUser(req.id);
         const isDefined = <T>(x: T | undefined): x is T => x !== undefined;
@@ -584,7 +586,7 @@ export class GitpodServerEEImpl extends GitpodServerImpl {
 
         // For some reason, returning the result of `this.userDB.storeUser(target)` does not work. The response never arrives the caller.
         // Returning `target` instead (which should be equivalent).
-        return this.censorUser(target);
+        return this.censorUser(targetUser);
     }
 
     async adminDeleteUser(ctx: TraceContext, userId: string): Promise<void> {
diff --git a/components/server/src/config.ts b/components/server/src/config.ts
index d936304276f3b9..4c9c1d3543b710 100644
--- a/components/server/src/config.ts
+++ b/components/server/src/config.ts
@@ -18,11 +18,15 @@ import { log } from "@gitpod/gitpod-protocol/lib/util/logging";
 import { filePathTelepresenceAware } from "@gitpod/gitpod-protocol/lib/env";
 
 export const Config = Symbol("Config");
-export type Config = Omit<ConfigSerialized, "hostUrl" | "chargebeeProviderOptionsFile" | "licenseFile"> & {
+export type Config = Omit<
+    ConfigSerialized,
+    "blockedRepositories" | "hostUrl" | "chargebeeProviderOptionsFile" | "licenseFile"
+> & {
     hostUrl: GitpodHostUrl;
     workspaceDefaults: WorkspaceDefaults;
     chargebeeProviderOptions?: ChargebeeProviderOptions;
     builtinAuthProvidersConfigured: boolean;
+    blockedRepositories: { urlRegExp: RegExp; blockUser: boolean }[];
 };
 
 export interface WorkspaceDefaults {
@@ -152,6 +156,12 @@ export interface ConfigSerialized {
      * Key '*' specifies the default rate limit for a cloneURL, unless overriden by a specific cloneURL.
      */
     prebuildLimiter: { [cloneURL: string]: number } & { "*": number };
+
+    /**
+     * List of repositories not allowed to be used for workspace starts.
+     * `blockUser` attribute to control handling of the user's account.
+     */
+    blockedRepositories?: { urlRegExp: string; blockUser: boolean }[];
 }
 
 export namespace ConfigFile {
@@ -201,6 +211,15 @@ export namespace ConfigFile {
         if (licenseFile) {
             license = fs.readFileSync(filePathTelepresenceAware(licenseFile), "utf-8");
         }
+        const blockedRepositories: { urlRegExp: RegExp; blockUser: boolean }[] = [];
+        if (config.blockedRepositories) {
+            for (const { blockUser, urlRegExp } of config.blockedRepositories) {
+                blockedRepositories.push({
+                    blockUser,
+                    urlRegExp: new RegExp(urlRegExp),
+                });
+            }
+        }
         return {
             ...config,
             hostUrl,
@@ -214,6 +233,7 @@ export namespace ConfigFile {
                     ? new Date(config.workspaceGarbageCollection.startDate).getTime()
                     : Date.now(),
             },
+            blockedRepositories,
         };
     }
 }
diff --git a/components/server/src/user/user-service.ts b/components/server/src/user/user-service.ts
index 23929112f82aed..e35a97cc5792bd 100644
--- a/components/server/src/user/user-service.ts
+++ b/components/server/src/user/user-service.ts
@@ -269,6 +269,16 @@ export class UserService {
         return false;
     }
 
+    async blockUser(targetUserId: string, block: boolean): Promise<User> {
+        const target = await this.userDb.findUserById(targetUserId);
+        if (!target) {
+            throw new Error("Not found.");
+        }
+
+        target.blocked = !!block;
+        return await this.userDb.storeUser(target);
+    }
+
     async findUserForLogin(params: { candidate: Identity }) {
         let user = await this.userDb.findUserByIdentity(params.candidate);
         return user;
diff --git a/components/server/src/workspace/workspace-starter.ts b/components/server/src/workspace/workspace-starter.ts
index a953d9f55ab052..f396318c400418 100644
--- a/components/server/src/workspace/workspace-starter.ts
+++ b/components/server/src/workspace/workspace-starter.ts
@@ -219,6 +219,8 @@ export class WorkspaceStarter {
 
         options = options || {};
         try {
+            await this.checkBlockedRepository(user, workspace.contextURL);
+
             // Some workspaces do not have an image source.
             // Workspaces without image source are not only legacy, but also happened due to what looks like a bug.
             // Whenever a such a workspace is re-started we'll give it an image source now. This is in line with how this thing used to work.
@@ -332,6 +334,22 @@ export class WorkspaceStarter {
         }
     }
 
+    protected async checkBlockedRepository(user: User, contextURL: string) {
+        const hit = this.config.blockedRepositories.find((r) => !!contextURL && r.urlRegExp.test(contextURL));
+        if (!hit) {
+            return;
+        }
+        if (hit.blockUser) {
+            try {
+                await this.userService.blockUser(user.id, true);
+                log.info({ userId: user.id }, "Blocked user.", { contextURL });
+            } catch (error) {
+                log.error({ userId: user.id }, "Failed to block user.", error, { contextURL });
+            }
+        }
+        throw new Error(`${contextURL} is blocklisted on Gitpod.`);
+    }
+
     // Note: this function does not expect to be awaited for by its caller. This means that it takes care of error handling itself.
     protected async actuallyStartWorkspace(
         ctx: TraceContext,