President Trump’s energy deregulation could be at the mercy of a Democratic successor or simply stall out if the administration does not rush to shore it up this year, his top former energy advisers warn.

The administration is “running up against the problem that the majority of the deregulatory rules will not be final and fully litigated before the end of the first Trump term,” said Myron Ebell, the president’s former Environmental Protection Agency transition official. “And that means if President Trump is not re-elected, the next president can undo them much more quickly than he would otherwise be able to do if they were final and had been litigated.”