U.S. Rep. Ken Buck on Sunday joined with six fellow House Republicans signaling their opposition to GOP-led efforts to challenge Joe Biden’s election as president when Congress meets Wednesday to formally certify the Electoral College vote.

In a lengthy statement issued soon after the new Congress was sworn in, Buck and six other prominent conservatives – including U.S. Reps. Thomas Massie of Kentucky, Chip Roy of Texas and Tom McClintock of California – say the Constitution specifies that states select presidential electors, not Congress, leaving Congress without the authority to change the results.

The statement comes a day after a dozen Senate Republicans, led by U.S. Sens. Josh Hawley of Missouri and Ted Cruz of Texas, said they are signing on to an effort to overturn President Donald Trump’s 306-232 Electoral College loss to Biden.

The signers of the statement also say they are “outraged at the significant abuses in our election system” and call it “imperative” that questions about the conduct of elections in battleground states be answered.

But Buck and the other Republicans make clear that unless state legislatures decide to submit slates of Trump electors, they don’t believe Congress can do anything other than count the votes.

“Congress has one job here: to count electoral votes that have in fact been cast by any state, as designated by those authorized to do so under state law,” the lawmakers wrote.

“Accordingly, our path forward is also clear. We must respect the states’ authority here. Though doing so may frustrate our immediate political objectives, we have sworn an oath to promote the Constitution above our policy goals. We must count the electoral votes submitted by the states.”

The statement’s other signers are U.S. Reps. Kelly Armstrong of North Dakota, Mike Gallagher of Wisconsin and Nancy Mace of South Carolina.

All 50 states have certified the election results, and electors for Biden and Trump met as planned in December to cast the votes Congress is scheduled to count on Wednesday. In addition, nearly 60 lawsuits filed by Trump and his allies challenging the results have been tossed by judges and the U.S. Supreme Court.

The statement puts Buck, the chairman of the Colorado GOP, squarely at odds with freshman U.S. Rep. Lauren Boebert, the state’s newest Republican member of Congress, over Trump’s extraordinary efforts to retain power despite losing the election.

Boebert, who was sworn in to her first term Sunday afternoon, announced on Dec. 24 that she plans to join dozens of other House Republicans objecting to Biden’s win. Buck said the same day that he would not object to the election results, but the joint statement released Sunday is the first indication he outright opposes the effort.

U.S. Rep. Doug Lamborn, Colorado’s other Republican member of Congress, hasn’t responded to multiple inquires about whether he’ll join in challenging congressional certification of Biden’s win.

With at least one objection in each chamber at Wednesday’s session, the House and Senate will be forced to vote on whether to certify the presidential results, though neither is expected to reverse Biden’s win.

Also Sunday, a bipartisan group of 10 senators issued a joint statement saying the “election is over” and calling on their colleagues to certify Biden’s win.

“At this point, further attempts to cast doubt on the legitimacy of the 2020 Presidential election are contrary to the clearly expressed will of the American people and only serve to undermine Americans’ confidence in the already determined election results,” the senators said.

That statement’s signers include Republican U.S. Sens. Susan Collins of Maine, Bill Cassidy of Louisiana, Lisa Murkowski of Alaska and Mitt Romney of Utah; Democratic U.S. Sens. Dick Durbin of Illinois, Maggie Hassan of New Hampshire, Joe Manchin of West Virginia, Jeanne Shaheen of New Hampshire and Mark Warner of Virginia; and Independent Sen. Angus King of Maine.

Buck and McClintock were the only participants in the statement from the House Republicans who also signed on to a brief supporting a Texas lawsuit asking the U.S. Supreme Court to throw out state electoral results. The Supreme Court rejected that lawsuit last month.