Billionaire entrepreneur Elon Musk is due to interview Republican presidential candidate Donald Trump on the X social media network on Monday in an event that could inject more surprises into the turbulent US presidential election.

The interview, scheduled for 8pm Eastern Time (0000 Tuesday GMT), could provide the former president an opportunity to seize the limelight at a time when his campaign is seen as sagging.

His Democratic rival for the November 5 election, Vice President Kamala Harris, has erased Trump’s lead in opinion polls and energised Democratic voters with a series of high-energy rallies.

The interview on Musk’s social media platform could allow Trump to reach a different audience than the conservative faithful who attend his rallies and watch his interviews on Fox News. However, similar events on the platform have been plagued by technical problems.

“Am going to do some system scaling tests tonight & tomorrow in advance of the conversation,” Musk wrote on the platform.

The interview will be hosted live using Trump’s official X account, his campaign said on Sunday. Trump’s access to his account, @realDonaldTrump, was restored a month into Musk’s ownership of X after being suspended by the platform’s previous owners following the January 6, 2021, attack on Congress by his supporters.

Trump frequently posts on his Truth Social social media platform, which was launched in February 2022. On Monday morning, Trump returned to X for the first time in a year, posting an ad that highlighted his claim that the four criminal prosecutions he faces are politically motivated.

His last X post before Monday was one in August 2023 appealing for donations and showing a mug shot after he was booked at an Atlanta jail in relation to felony charges tied to his attempts to overturn his 2020 election defeat in Georgia.

Musk could prove to be an unusual interviewer. The world’s richest person backed Democratic President Joe Biden in 2020 but has tacked rightward since and endorsed the Republican following the attempted assassination of Trump in July.

Musk, who heads electric car company Tesla Inc, also started a fundraising organisation to support Trump’s campaign. The political action committee is now under investigation in Michigan for possible violations of state laws on gathering voter information.

Trump, a longstanding critic of electric vehicles, shifted gears after Musk’s endorsement.

“I’m for electric cars. I have to be, because Elon endorsed me very strongly. So I have no choice,” Trump said at an early August rally.

United Auto Workers President Shawn Fein, campaigning in support of Harris, called Trump a “sellout”.

The Biden administration has worked to popularise electric vehicles through tax breaks and other support as part of its broader goal of reducing carbon emissions blamed for climate change.

Republicans in Congress have opposed those subsidies. Senator JD Vance, Trump’s vice presidential running mate, said the Biden policy merely subsidises rich people who purchase the cars.

Advertisers have fled X since Musk bought it in 2022 and subsequently reduced content moderation which has resulted in a dramatic increase in hate speech, civil rights groups have said.

In the meantime, the entrepreneur has been involved in a swirl of additional controversies. He has falsely accused Biden and the Democratic Party of opening US borders to undocumented immigrants in a ploy to boost the number of potential Democratic voters. Non-citizens are not allowed to vote in federal elections.

Musk in November 2023 endorsed an antisemitic post on X that said members of the Jewish community were stoking hatred against white people.

He defended himself, saying the user was speaking “the actual truth”. Musk has also attacked the Anti-Defamation League, a nonprofit that works to fight antisemitism, accusing it, without evidence, of being responsible for a drop in advertising on X.