WASHINGTON — House Speaker John Boehner’s carefully planned effort to paint Republicans as unified behind a tax and spending plan was in turmoil Thursday night, as he was unable to find enough votes from his own members to pass a tax increase on the wealthy.

Boehner’s sudden decision not to vote was a stunning setback for the speaker, who had hoped his “Plan B” would give him fresh momentum heading into a crucial round of talks with President Barack Obama to avoid the fiscal cliff.

But the warning signs were too numerous to ignore. Conservatives balked at his plan to tax those earning more than $1 million. Even after Republican leaders agreed to allow a vote on a spending plan, that plan passed by only a 215-209 vote.

About an hour and a half later, after tense closed-door meetings with Republican leaders, Boehner issued a statement.

“The House did not take up the tax measure today because it did not have sufficient support from our members to pass,” he said.

“Now it is up to the president to work with Senator Reid on legislation to avert the fiscal cliff. The House has already passed legislation to stop all of the January 1 tax rate increases and replace the sequester with responsible spending cuts that will begin to address our nation's crippling debt. The Senate must now act."

The Senate does not plan to act.

Tax cuts are due to expire at the end of the year, and automatic spending cuts will kick in Jan. 2 unless alternatives are adopted.

No final action is expected anytime soon, as the Senate is scheduled to leave Friday until Dec. 27 and the House is at a partisan impasse.

The House votes were always a gamble. Democrats made it clear throughout the day that the Thursday tax and spending measures were dead in the Senate, “bills to nowhere,” as House Democratic Leader Nancy Pelosi, D-Calif., put it.

Republican leaders were hoping the votes would have value, showing they stood together in backing tough spending measures while accepting some tax increase for the wealthy. But Boehner had to struggle to win over wary conservatives opposed to any tax increase and seeking even more spending cuts.

The vote came during a day of familiar but intensifying partisan oratory, flavored with expressions of hope that a deal was in the works.

Democrats howled that the votes were little more than a sideshow that demonstrated how Republicans were delaying progress so they could score political points.

The House bill would have only millionaires pay the pre-Bush top rate of 39.6 percent, up from the current 35 percent. Everyone else would continue to pay at current rates. The spending bill replaces the automatic cuts with several different adjustments, including eliminating fraud, waste and abuse in federal programs. The bill also would cancel the automatic cuts in defense and some domestic programs, and replace those cuts with reductions in a series of other programs.

The Democratic-led Senate has no plan to consider the bills, said Majority Leader Harry Reid, D-Nev.

“It is dead on arrival here in the Senate,” said Sen. Patty Murray, D-Wash. Virtually all the spending plan had passed the House months ago and went nowhere in the Senate.

Democrats were downright angry at all the maneuvering. Why, they asked, is Boehner wasting time cajoling members of his own party – he worked hard to convince wavering anti-tax conservatives – to back bills going nowhere?

“Republicans are wasting time on political stunts,” Reid said.

At the White House, Press Secretary Jay Carney said Boehner’s bill, called Plan B, was a "multi-day exercise in futility," but he insisted that there was "still an opportunity for compromise on a ‘big deal.’"

Thursday’s Republican approach is a time-worn strategy, putting people on the record at a crucial point during negotiations, to show their rivals and the public that they’re willing to take a stand, no matter how hopeless. The debate allowed them to go before the House – and the American public – insisting that they have a position and the Democrats don’t.

“President Obama and Senate Democrats haven’t done much of anything. Their Plan B is to slow-walk us over the fiscal cliff,” Boehner told a news conference. Obama did offer a plan earlier this week that includes $1.2 trillion in new revenue and $1.22 trillion in spending cuts.

Lesley Clark of the Washington Bureau contributed.