President Donald Trump threatened to shut down the government if lawmakers do not fully fund his proposed border wall and enact his immigration priorities.

I would be willing to “shut down” government if the Democrats do not give us the votes for Border Security, which includes the Wall! Must get rid of Lottery, Catch & Release etc. and finally go to system of Immigration based on MERIT! We need great people coming into our Country! — Donald J. Trump (@realDonaldTrump) July 29, 2018

Trump’s Sunday tweet is likely to spark a high stakes showdown with Democratic lawmakers who have pledged not to give in to his demands. The fight could lead right into the November midterm elections and put immigration as a centerpiece issue in the last stages of the campaign season.

Trump has long been frustrated by lack of effort to fully fund his proposed $25 billion wall along the U.S.-Mexico border. The White House originally tried to enact wall funding and immigration priorities by tying demands to an expiration of DACA. The DACA program allowed hundreds of thousands of illegal immigrants brought to the U.S. as children to remain in the U.S. and work without consequences.