Conservative Republicans put pressure on House Speaker John Boehner on Wednesday to reject any "fiscal cliff" deal with Democrats that raises taxes but doesn't make significant cuts in federal spending.

"What we are saying is that it is ridiculous for Republicans to accept any tax rate increase if there are no real cuts," Rep. Raul Labrador, R-Idaho, said during a forum featuring nine conservative House lawmakers.

Their warning to the speaker comes just as congressional leaders are suggesting that negotiations with the White House over deficit reduction are making so little progress that they may not have a deal by Christmas.

Conservatives said Boehner should be prepared to adjourn the House at the end of the year without a deal if Democrats refuse to agree to trillions in cuts and a plan to reform entitlement spending. If Congress fails to reach a deal before Jan. 1, massive tax increases and automatic spending cuts will start to kick in, affecting millions of Americans.

"It's my opinion that a bad deal is worse than no deal at all," said Rep. Cynthia Lummis, R-Wyo. Any tax increases or spending cuts scheduled to kick in can be undone by a new Congress next year.

"I'd rather see cooler heads prevail in January," she said.

Boehner, however, signaled Wednesday that he is planning to keep the House working nearly ever day leading up to the end of the year. He warned staff and lawmakers that they would have to cut their Christmas break short and return to the Capitol on Dec. 27 if no deal is reached before the holiday.

Boehner said he cannot find common ground with President Obama, who late Tuesday offered a new proposal to congressional Republicans that reduced the size of his proposed tax increase from $1.6 trillion to $1.4 trillion.

"The president and I had a pretty frank conversation about just how far apart we are," Boehner said.

While many House Republicans, including Lummis, say they trust Boehner to produce a deal that upholds the party's principles of lower taxes and spending, they also cautioned that the speaker can't give up too much at the bargaining table without risking a intraparty revolt.

Some of the discontented lawmakers appeared Wednesday at a forum for conservatives that included two of the four conservative lawmakers Boehner earlier booted from their committee assignments because they voted against Republican legislation.

Rep. Justin Amash, R-Mich., a Tea Party favorite whom Boehner removed from the Budget Committee after he voted against a plan to raise the nation's borrowing limit, said the speaker must insist on bigger cuts.

"We are not doing the best job we can do," Amash said.

Rep. Tim Huelskamp, R-Kan., who was tossed off the Agriculture Committee, suggested he won't back Boehner again for House speaker when the new Congress convenes in January because polls in his conservative district show that 88 percent of his constituents don't support Boehner.