Elon Musk’s feud with President Donald Trump has reignited, with the tech billionaire threatening to launch a new political party and Trump suggesting Musk could be punished for his opposition.

Trump late Monday night fought back, suggesting his administration may investigate Musk’s companies’ massive government contracts. On Tuesday at the White House, Trump said Musk risked losing “a lot more” than government subsidies and threatened that the Department of Government Efficiency that Musk once led may “go back and eat Elon.”