A federal judge temporarily blocked a move by the US government to ban downloads of Chinese messaging app WeChat, stating a lawsuit by users raised serious questions that an executive order threatens their free speech rights.

The judge issued a preliminary injunction blocking the Department of Commerce from requiring Apple and Google to remove WeChat from their app stores, noting the ban had a disproportionate impact on free speech relative to the government’s national security concerns.

A ban on WeChat was due to come into effect yesterday (20 September).

While acknowledging the government’s overarching national security interest is significant, the judge stated “it has put in scant little evidence that its effective ban of WeChat for all US users addresses those”.

She added there are obvious alternatives to a complete ban, such as barring WeChat from government devices as Australia has done, or taking other steps to address data security.

The plaintiffs claim the ban violates the First Amendment because WeChat is effectively the only means of communication for many in the community, given China bans other apps and Chinese speakers with limited English proficiency have no other options.

WeChat was used by nearly 20 million people in the US in August, data from Apptopia showed. Globally, monthly active users rose 6.5 per cent year-on-year to 1.2 billion at end-June.