U.S. President Donald Trump, addressing Republican lawmakers directly on Monday, pressed them to enact sweeping new voting restrictions as a way to “guarantee” victory in November’s midterm elections, saying he would refuse to sign new bills into law until they do.

The SAVE America Act would impose new voter restrictions including a requirement for proof of citizenship for people registering to vote. It first emerged two years ago in response to Trump’s false claims that people in the country illegally were voting in U.S. elections.

“It’ll guarantee the midterms. If you don’t get it, big trouble, my opinion,” Trump told House Republicans gathered at his Doral golf club in Miami to discuss the president’s legislative agenda.