Tesla and Twitter owner Elon Musk called on U.S. voters to cast their ballots in favor of Republican candidates in the midterm elections.
"Shared power curbs the worst excesses of both parties, therefore I recommend voting for a Republican Congress, given that the Presidency is Democratic," Musk tweeted to his 114 million followers.
"Hardcore Democrats or Republicans never vote for the other side, so independent voters are the ones who actually decide who's in charge!"
The Tesla boss's stewardship of Twitter — one of the world's leading platforms for discourse and activism — has prompted warnings over its political neutrality.
Musk has indicated he plans to lift the ban on former president Donald Trump, though not before the midterm vote on Tuesday.
Trump was banned for allegedly inciting last year's attack on the Capitol by a violent mob seeking to overturn the results of the 2020 presidential election.
Musk's sacking of many Twitter staff has also underlined fears that the site will be flooded by hate speech and disinformation, leading some advertisers to back away.
His tweet on Monday represented the first time the head of a major social media platform explicitly endorsed a U.S. political party.
President Joe Biden's Democrats face a steep battle to retain control of Congress in Tuesday's vote.
Nonpartisan election forecasters and polls suggest Republicans have a very strong chance of winning a majority in the House of Representatives, with control of the Senate likely to be more closely fought.
Musk has previously said he would vote for Republicans but says he backs moderates on both sides of the aisle.
In April, Musk said that for "Twitter to deserve public trust, it must be politically neutral, which effectively means upsetting the far right and the far left equally."
Musk frequently comments on U.S. politics.
He said previously that he was leaning toward supporting Florida's Republican Governor Ron DeSantis for president in 2024 and that former president Donald Trump was too old to serve as president again.