Washington (CNN) John Boehner and his allies scrambled to lock down support for his reelection as Speaker on Tuesday morning as the small army of conservative lawmakers promising to vote against him continued to expand.

A senior House GOP leadership source tells CNN that Boehner is reaching out to members to urge support as they try to stave off the coup attempt. Voting was underway Tuesday afternoon with several Republicans already voting for people other than Boehner.

Bad weather and the funeral proceedings for former New York Gov. Mario Cuomo, however, made conservatives' challenge tougher as the two incidents combined ensured some lawmakers wouldn't make the vote. With fewer lawmakers voting, conservatives will need more Boehner opponents to force the vote to a second ballot.

Still, Monday morning conservatives were optimistic as more prominent members in their ranks came out opposed to the Speaker. Rep. Justin Amash, one of the original dozen that opposed Boehner for speaker in 2013, said in a Facebook post that while "Speaker Boehner has given his best to our conference...it's time for Republicans to change our leadership."

Incoming Rep. Curt Clawson, via tweet ; South Carolina Rep. Jeff Duncan, via Facebook ; and Kansas Rep. Tim Huelskamp, via tweet , also joined the 10 lawmakers that announced their opposition to Boehner over the weekend and into Monday. Conservatives say they've locked down at least a dozen and as many as 15 certain no-votes, with more expected when the vote happens Tuesday afternoon.

Florida Rep. Ted Yoho, who is just starting his second term in the House, is one of the conservatives collaborating to spark a second round of voting, and has offered him up as an alternative to the Ohio Republican, along with Texas Rep. Louie Gohmert.

While Boehner's allies have said they are confident a second vote won't happen, about a dozen Republicans have indicated publicly they will vote against Boehner.

"We're at over a dozen right now and you're going to see more people get on and decide not to vote for the current leadership," Yoho said Tuesday on CNN's New Day. "It's time for new leadership."

Rep. Louie Gohmert of Texas is also throwing his name into the running to overthrow Boehner.

Yoho painted his challenge to the establishment leadership as a "vote against the status quo" and a rebuke of Boehner's leadership, which Yoho and his allies have called weak, short-sighted and eschewing regular order in favor of cobbled compromise.

Yoho insisted his message is resounding with other Republicans.

"We announced on Saturday that we were going to throw my name in the hat and you've seen a groundswell, a grassroots movement of people saying, 'You know what, I appreciate you offering us an alternative because I'm tired of the status quo,'" Yoho said. "It's either a vote for the status quo or for a new direction for the Republican Party."

But they admit the public nature of the vote could cause all the opposition to fall apart at the final moments, and they're not yet predicting victory.