The Mozilla Foundation and a group of rights groups and non-profits have penned an open letter to Facebook and Google urging them to halt political advertising until after the upcoming UK General Election.

The letter argued that there won’t be time in the current parliament for the urgent legislation on political ads that the UK Electoral Commission, Information Commissioner’s Office (ICO) and the cross-party DCMS Select Committee have called for.

“This legislative blackspot is particularly concerning in light of Facebook’s recent policies to allow politicians to openly publish disinformation through ads. Equally concerning is the lack of transparency as to what data is being used to target ads, and how such ads are being targeted,” the letter continued.

“We are aware that these policies are subject to debate both inside and outside the company. While that debate continues, people in the UK are left in uncertainty about whether they can trust what they see on the platform.”

The letter’s authors pointed to precedent in this space, with Google blocking political ads two weeks before polling in the Irish referendum and during the entirety of the recent Israeli and Canadian election periods.

“Again, this call is not about a permanent ban on political and issue-based ads; indeed, political ads are not inherently problematic. But the online advertising model, which depends on vast collection of data and opaque ad targeting systems is not fit for purpose and thus fundamentally undermines trust in political advertising,” it concluded.

“It is a request to take temporary measures to ensure that your platforms are not complicit in exploiting electoral laws MPs themselves have described as ‘unfit for purpose’.”

Mark Zuckerberg has come in for heavy criticism of late for effectively defending the right of politicians to lie in their ads, saying: “I don’t think most people want to live in a world where you can only post things that tech companies judge to be 100% true.”

Facebook rejected a request from Presidential hopeful Joe Biden to remove a Trump campaign ad containing misinformation about the former Veep.

Last month, Twitter stepped up the pressure on Facebook by announcing a ban on political advertising on its platform. However, experts argued that Twitter doesn’t host many political ads anyway, and the move would do nothing to stem the flow of misinformation ahead of elections coming from bot accounts.