Billionaire philanthropist George Soros has called for Facebook CEO Mark Zuckerberg and COO Sheryl Sandberg to “be removed from control” of the company in an open letter published in the Financial Times.

Soros accused Zuckerberg of engaging in “some kind of mutual assistance arrangement with Donald Trump that will help him to get re-elected” by continuing to run political ads on Facebook. Twitter CEO Jack Dorsey has taken the opposite approach, banning all political advertising worldwide last October.

We’ve made the decision to stop all political advertising on Twitter globally. We believe political message reach should be earned, not bought. Why? A few reasons…🧵 — jack 🌍🌏🌎 (@jack) October 30, 2019

Facebook, meanwhile, continues to run them, while exempting them from fact-checking and allowing campaigns to target their ads at specific groups of voters.

It does keep a record of them in an Ad Library, which shows how much money politicians are spending on Facebook ads and the messages they’re paying to amplify.

However, even this meager requirement was evaded this week, after a series of Instagram meme accounts posted sponsored ads for Michael Bloomberg’s presidential campaign. Facebook told the Verge and BuzzFeed News that it would not be adding these posts to the Ad Library — unless the creator paid to boost them.

[Read: Facebook and Zuckerberg keep getting ‘freedom of expression’ wrong]

Soros has urged the company to stop accepting every form of political advertising ahead of the US elections on November 4.

“If there is any doubt whether an ad is political, it should err on the side of caution and refuse to publish,” he wrote. “It is unlikely that Facebook will follow this course.”

Soros vs Facebook

Soros has frequently lambasted Facebook for skewing democracy, and manipulating users for commercial purposes.

In 2018, the company’s policy chief admitted that the social network had hired a public relations firm to attack Soros — although Zuckerberg claimed he only learnt of this when it was reported in the New York Times.

Credit: Heinrich-Böll-Stiftung Soros previously said that “Facebook helped Trump to get elected and I am afraid that it will do the same in 2020.”

The latest salvo from Soros comes as Zuckerberg is meeting EU lawmakers in Brussels.

The Facebook founder has publically acknowledged that Big Tech needs further regulation and conceded that his company may have to pay more tax in Europe in an attempt to win friends among European lawmakers. Early reports suggest that they’ve been unimpressed by his charm offensive.

It has certainly failed to convince Soros.

“Mark Zuckerberg should stop obfuscating the facts by piously arguing for government regulation,” he wrote.

Read next: Kashmiri cops filed a case against people using VPN and social media