A conservative firebrand has officially filed to run for the Montana Senate in the heated contest to unseat Democrat Sen. Jon Tester.

Rep. Matt Rosendale, R-Mont., made the long awaited announcement Friday on X, formerly known as Twitter. 

“We’ve made great accomplishments in the House, only to see them die at the hands of Mitch McConnell and Chuck Schumer in the Senate,” he wrote in a post.

FORMER NAVY SEAL SAYS DEMS MEDDLING IN HIS SENATE RACE ‘TO DISTRICT MONTANA VOTERS’ FROM ‘TWO-FACED’ OPPONENT

Rosendale’s bid stirs up the state’s Republican primary race, where he will be challenging former Navy SEAL Tim Sheehy for the nomination.

Sheehy, a first-time candidate, has already gained endorsements from Sen. Steve Daines, R-Mont., Rep. Ryan Zinke, R-Mont., and Gov. Greg Gianforte.