Susan Walsh/AP Photo

ABC News' Shushannah Walshe and Alex Lazar report:

WASHINGTON - The list of members of Congress who would vote on a bill to fund the government without conditions attached, also known a "clean" continuing resolution, is constantly changing.

Five GOP members - Reps. Devin Nunes, R-Calif.; Lou Barletta, R-Pa.; Mike Simpson, R-Idaho; Leonard Lance, R-N.J.; and Randy Forbes, R-Va. - who had previously been on record in support of a clean funding measure, each said Monday and Tuesday they had changed their minds or that their previous positions were misconstrued.

On Sunday, Speaker John Boehner told ABC's George Stephanopoulos on "This Week" that "there are not the votes in the House to pass a clean CR." Since then, several Republicans who were on record favoring such a bill now say they are against it - though a bare majority of the full House remains in support, according to ABC News reporting.

Nunes told reporters Monday at the Capitol that his support for a clean bill was contingent on the government not shutting down.

"My position has not changed at all," Nunes told reporters in the Speaker's Lobby Monday evening during votes. "My preference was a clean CR, before we did the shutdown. I've been out on every major television show stating this over and over again. It's not news. There's not going to be a vote [on a clean CR]. There's not the votes for it. If there was a serious negotiation with Democrats going on, maybe, but there's not. They're doing gimmicks."

On Monday, Nunes' press secretary Jack Langer also confirmed to ABC News that the California Republican "does not support or advocate a clean CR."

On Monday, Barletta's press secretary Tim Murtaugh told ABC News the congressman would support a "clean" bill "should it come up," but by Tuesday, Murtaugh said Barletta no longer feels that way.

"While he once expressed openness to a no-strings-attached CR, a growing number of Democrats have emerged who will support a repeal of Obamacare's medical device tax. That would open the government, and also get rid of a job-killing, cost-raising funding source of Obamacare," Murtaugh said in an e mail to ABC News. "Sometimes being in Congress means pursuing the art of the possible. This would be a CR that can pass the House and Senate."

Lance's office had previously told ABC News he would support a "clean" CR, but by Monday evening his position had changed. His chief of staff Todd Mitchell told ABC News "the congressman's official position is he doesn't support a clean CR at this time."

"He would like there to be negotiations between speaker, president, and Senate leadership," Mitchell said.

Simpson was originally on ABC's list because he put out a statement saying he "could support a very short-term clean funding measure, perhaps one or two weeks, while we continue to negotiate on a longer-term bill that addresses priorities we believe are important."

When asked if Simpson would support a longer term clean CR if it came to a vote, Simpson's communications director Nikki Watts told ABC she could not answer questions about "hypothetical" legislation, but she would not put Simpson on that list. At that point on Monday, Simpson was removed from ABC News' list of clean CR backers.

Forbes made it on to our list because of a story in The Virginian Pilot, where it said the Virginia Congressman would support a clean resolution.

"You wake up in the morning and you realize that both teams played really poorly the night before in the game," Forbes told the newspaper last week. "I think that's what the American people see happening here. … Unfortunately for us, this is not a game. This is real lives of people. … I think there's enough blame to go around with Republicans and Democrats."

But, on Monday an aide to Forbes said this was not his stance and he would "not support the CR as amended by the Senate and he would need to read any other iteration of a proposal providing full funding for the government before he could say where he stands on it."

The aide said Forbes actually supports his own legislation, which would fund the entire government, except for the IRS.

ABC's John Parkinson contributed reported.