The Liberal Democrats are pushing for a ban on MPs accepting payments from X as part of a proposed wider crackdown on what Ed Davey will call a “serious threat” to UK democracy from Donald Trump’s US and other countries.

Announcing the plan on Tuesday, the Lib Dem leader renewed his attacks on Reform UK – a series of whose MPs have taken money from X – calling it “a franchise of Maga politics” rather than a British political entity.

Under proposed amendments to the government’s representation of the people bill, now going through parliament, there would also be a ban on anyone who has served in a foreign administration donating to UK political parties, thinktanks or campaign groups.

This follows a promise by the US state department to fund parties and thinktanks seen as aligned with Trump’s hard-right agenda, particularly in Europe. The now-defeated Hungarian government of Viktor Orbán also supplied money to a series of rightwing thinktanks and political figures, including in the UK.

Speaking at a press conference in London on Wednesday afternoon, Davey warned that MPs receiving money from X was a way for the platform’s owner, Elon Musk – who has repeatedly endorsed far-right and racist ideas – to funnel money into the UK’s political system.

Under Musk, verified X users can receive payments based on views and engagement with their posts with a built-in algorithm that tends to promote controversial and hard-right content.

Farage’s entry in the most recent register of interests showed payments from X totalling more than £12,000 in recent months, with his fellow Reform MPs Richard Tice and Lee Anderson also receiving money for their posts.

Rupert Lowe, the MP who left Reform and now leads the overtly far-right Restore Britain party, receives the most money from X, with the register of interests showing more than £37,000 in payments.

“British democracy is under serious threat from powerful men outside our country who are trying to destroy it – Donald Trump, Elon Musk, Vladimir Putin,” Davey said. “And there are dangerous forces inside our politics who are aiding and abetting that destruction.

“Nigel Farage and Reform UK are not a British political movement, they are a franchise of Maga politics, trying to import Trump’s divisive agenda into our communities. These are not the people we want running our councils.

“Even worse, they are being funded by Elon Musk, who has incited violence on Britain’s streets. Nigel Farage, Richard Tice, Lee Anderson and Rupert Lowe are all taking money from Musk via his American company X. We must close that loophole. Elon Musk should not be able to use his money to interfere in British politics through the back door.”

While Davey has been a regular critic of Trump, including in parliament, his party has stepped up its attacks on Farage and Reform for their closeness to the US administration ahead of elections to the Scottish and Welsh parliaments and English councils on 7 May.

Polling shows Trump is increasingly unpopular with the UK public, particularly after the US-Israeli attack on Iran, which has developed into a stalemate that threatens the global economy and supplies of fuel and goods such as fertiliser.

The Lib Dems aim to submit amendments to the representation of the people bill under a “defending democracy” banner. The bill already contains measures to restrict overseas political donations, as well as lowering the voting age to 16 UK-wide.