The billionaire’s Trump-supporting Pac will give the money to those who sign a petition that encourages Republicans in Pennsylvania to register to vote

Elon Musk said his Trump-supporting political action committee – America Pac – will give $1m every day until election day to someone who signs his petition that effectively encourages Republicans in the key battleground state of Pennsylvania to register to vote.

The commitment, which started on Saturday as Musk handed a lottery-style check to the first winner of his contest at a town hall event, could mean Musk is on the hook for $17m if he remains the sole donor to his own Pac.