Elon Musk has started a petition to promote "free speech and the right to bear arms," and is offering US voters who sign it a prize of $1 million (€920,000) every day until the November 5 election.

The owner of X, previously Twitter, handed over the first check on Saturday to a man in Pennsylvania — a state considered a "must-win" for both Republicans and Democrats. He gave a second on Sunday.

The billionaire supporter of Donald Trump has urged registered voters in key swing states to sign the petition.

Musk said he would select one random person each day from the list of signatures and award them the million-dollar prize.

Speaking at a rally in the state, Musk said his aim was to get between 1 million and 2 million voters in swing states to sign the petition "because I think this sends a crucial message to our elected politicians."

Musk backs Trump

Musk's campaign appears to encourage Republican supporters to register to vote.

Observers have suggested that such a stunt could potentially contravene laws that prohibit paying people to register to vote.

According to the Federal Election Commission, Musk has donated around $75 million over the past three months to a political action committee he set up to support the Trump campaign, called America PAC.

The CEO of Tesla and SpaceX has repeatedly lauded Trump — who has indicated he would tap Musk to run a budget efficiency commission if he is reelected — while publicly criticizing Democratic hopeful Kamala Harris.

Correction: The original version of this story contained a spelling mistake "fist" instead of "first," and "through" instead of "thrown." This has now been corrected.

zc/jcg (dpa, AFP)