A California judge has temporarily blocked a US Department of Commerce ban on Chinese social media app WeChat just hours before it was due to be implemented, dealing a blow to Donald Trump’s efforts to curb use of the app due to security concerns.

Judge Laurel Beeler of the Northern District of California granted a nationwide injunction on Sunday suspending the order for Apple and Google to remove WeChat, which is owned by Chinese technology group Tencent, from their app stores. The order had been due to come into force later in the day.

The plaintiffs, primarily a group called the US WeChat Users Alliance, said in their lawsuit that the ban, which would have made the app essentially unusable in the US, violated First Amendment-protected freedoms of speech, especially for Chinese Americans.