If shutdown stalemate continues, Senate Republicans should nix the 60-vote rule to allow legislation to pass with 51 votes, President Trump tweeted Sunday.

Senate Majority Leader Mitch McConnell, however, has long firmly opposed the rule change.

Great to see how hard Republicans are fighting for our Military and Safety at the Border. The Dems just want illegal immigrants to pour into our nation unchecked. If stalemate continues, Republicans should go to 51% (Nuclear Option) and vote on real, long term budget, no C.R.’s!

— Donald J. Trump (@realDonaldTrump) January 21, 2018

The Senate Republican Conference continues to oppose using the “nuclear option” to eliminate the ability to filibuster legislation, a senior Senate GOP aide confirmed Sunday morning.

The Senate reconvenes at 1 p.m. Sunday, with a possible vote by 1 a.m. Monday.

Senators had failed on Friday to cut off debate on a House-passed bill that would have averted a government shutdown and extend funding another four weeks. Efforts to do what was necessary to reopen the government on Saturday also fell short.

Watch: McConnell, Durbin Make Their Case As Shutdown Looms