Elon Musk has caused outrage in Berlin after appearing to endorse the far-right, anti-immigrant Alternative für Deutschland.

Musk, who has been named by Donald Trump to co-lead a commission aimed at reducing the size of the US federal government, wrote on his social media platform X: “Only the AfD can save Germany.”

He reposted a video by a German rightwing influencer, Naomi Seibt, who criticised Friedrich Merz, the leader of the conservative Christian Democrats who has the best chance of becoming the next German chancellor, and praised Javier Milei, the libertarian president of Argentina.

The German health minister, Karl Lauterbach, called Musk’s decision to wade into the German political debate weeks before the snap election “undignified and highly problematic”.

Europe’s largest economy is expected to go to the polls on 23 February after the collapse last month of Olaf Scholz’s centre-left coalition. The AfD is running in second place in opinion polls. Elements of the party have been classed as rightwing extremists by Germany’s domestic intelligence services, and mainstream parties have vowed to refuse to work with the AfD at national level.

The German government issued only a perfunctory response to Musk’s post, noting that it had registered it, but a spokesperson refused to add any further comment.

At a press conference in Berlin, Scholz responded indirectly to the post, saying: “We have freedom of speech here. That also applies to multimillionaires. Freedom of speech also means that you’re able to say things that aren’t right and do not contain good political advice.”

The German former MEP Elmar Brok dismissed Musk’s comment as “the world domination fantasies of the American tech kings”.

Late on Friday, after at least two people were killed and scores wounded in a suspected terror attack on a Christmas market in the German city of Magdeburg, Musk doubled down, tweeting: “Scholz should resign immediately. Incompetent fool.”

Lauterbach accused Musk of election interference and called for authorities to “keep a close eye on the goings-on on X”.

He said: “It is very disturbing, the way in which the platform X, which I use very intensively myself, is increasingly being used to spread the political positions and goals of Mr Musk.”

The most direct response to the Musk tweet came from Christian Lindner, the head of the pro-business Free Democrats (FDP), who was sacked as finance minister by Scholz over deep disagreements around fiscal management.

Lindner wrote on X: “Elon, I’ve initiated a policy debate inspired by ideas from you and Milei. While migration control is crucial for Germany, the AfD stands against freedom, business – and it’s a far-right extremist party. Don’t rush to conclusions from afar. Let’s meet, and I’ll show you what the FDP stands for. CL”.

In May, the AfD was expelled from a pan-European parliamentary group of populist far-right parties after a string of controversies, including a comment by the senior AfD figure that the Nazi SS were “not all criminals”.

The ID group, which includes France’s far-right National Rally, Italy’s Lega, Austria’s Freedom party, Geert Wilders’ Dutch Freedom party and Vlaams Belang in Belgium, said it “no longer want[ed] to be associated” with such incidents.

Musk has previously expressed backing for other anti-immigration forces across Europe, including the UK’s Reform party and Italy’s prime minister, Giorgia Meloni.

He has also previously voiced enthusiastic support for Milei, who in his first year as Argentina’s president has cut public spending and axed tens of thousands of public sector jobs, and plunged many households into economic despair.

Alice Weidel, the head of the AfD, who is standing as its candidate for chancellor, reposted Musk’s comment, writing to him: “Yes! You are perfectly right @elonmusk!”

Referring to a recent interview she gave on Trump with the news organisation Bloomberg, Weidel said Musk should note “how socialist [Angela] Merkel ruined our country, how the Soviet European Union destroys the country’s economic backbone and malfunctioning Germany”. She wished Musk and Trump a happy Christmas and “all the best for the upcoming tenure”.

Last year Musk criticised the German government and its struggle to tackle illegal migration, one of the main topics on the election campaign agenda. He has also fired off personal jibes against Scholz and his economics minister, Robert Habeck.

This week Nigel Farage, the Reform UK leader, posted a photograph of himself and the party’s treasurer meeting Musk at Trump’s Mar-a-Lago residence in Florida and claimed Musk was prepared to provide financial support to bolster his party’s chances of entering government.