Senate Majority Leader Chuck Schumer (D-NY) vowed on Monday that he will push a vote on changing the Senate rules by January 17, Martin Luther King Jr. Day, if Republicans continue to oppose his party’s voting rights bill.

“If Republicans continue to block our efforts, The Senate will debate and consider changes to Senate rules on or before January 17, Martin Luther King Jr. Day, to protect the foundation of our democracy: Free and fair elections,” Schumer tweeted.

Schumer also sent a letter on Monday to the members of the Senate Democratic Caucus regarding the issue.