House Speaker John Boehner (R-Ohio) appealed in unusually aggressive terms to his wavering GOP colleagues in a closed-door meeting on Wednesday morning with just a week left to go until the debt ceiling must be raised or the country will default on its obligations.

At a meeting of GOP House members, the embattled Republican leader told his colleagues, many of whom had vowed to oppose his two-step bill to raise the debt limit that is expected hit the floor as soon as Thursday, to “get your ass in line.”

The meeting came as Boehner scrambled to rewrite his legislation the morning after a Congressional Budget Office analysis showed his plan would cut the deficit less than advertised.

In a closed-door meeting for the House GOP Conference in the basement of the Capitol, Boehner worked to rally support from skeptical conservatives, who have been subjected to intense pressure from tea party groups and others who say Boehner’s plan will not impose the kind of structural reform Republicans promised when they took control of the House in 2010.

With few options on the table except the plan advanced by Democratic Senate Majority Leader Harry Reid (D-Nev.), some of those conservatives now seem inclined to finally fall in line behind their leader.

Republican leaders told the group that they need to stay united and rally around the bill. Boehner also said his bill will be rewritten to either cut more from the deficit or to raise the debt ceiling by less than the $900 billion he had proposed earlier this week.

That way, his plan would hew to his promise to match the debt-ceiling hike with spending cuts. Members said leaders did not tell them which approach will be taken with the revisions.

“We’re making progress,” Boehner told reporters after Wednesday morning’s meeting. Asked whether he thought the CBO report had dealt a blow to his plan and whether a vote was still scheduled for Thursday, Boehner declined to say.

House Majority Leader Eric Cantor (R-Va.) said after the meeting that House Republicans “just had a very good conference.”

“Members are rallying around the speaker’s plan, and we’re going forward,” Cantor said. He declined to say whether he thought the plan would pass with the support of Republicans alone, saying only, “We will pass the speaker’s plan.”

There were signs Wednesday that Boehner was having some success at converting wary undecided votes into possible supporters.

After the meeting, several Republicans who had been wavering said they now back Boehner’s revised proposal — in part because they fear undercutting the speaker just days before the Aug. 2 deadline to raise the debt limit.

If the House plan were to founder because of lack of Republican support, it would leave only a proposal by Democratic Senate Majority Leader Harry M. Reid (Nev.) still standing.

Reid’s plan to raise the ceiling by $2.4 trillion would remove the pressure of a possible default from debates about reducing spending in coming months — a far less preferable option, several Republicans said.

“I’ve given this careful consideration, and I’ve decided this is what’s best for our country,” freshmen Rep. Scott Rigell (R-Va.), who had been undecided earlier in the week, said of Boehner’s plan. “I respect the process the leadership went through.”

Rep. Sean P. Duffy (R-Wis.) said he, too, had been persuaded to back the House GOP leadership plan.

“We came here to reduce the size of government and reduce spending, and this bill, I think, begins to accomplish that goal,” he said. “It’s by no means perfect. But it’s the best bill we have.”

A House Republican aide with knowledge of the meeting said that Boehner addressed the conference first. Cantor then spoke, followed by House Budget Committee Chairman Paul Ryan (R-Wis.) and House Majority Whip Kevin McCarthy (R-Calif.).

About 30 members spoke out at the gathering, six of whom said they had previously been leaning against the Boehner plan but were now supporting it, according the aide, who was not authorized to speak publicly about internal conference meetings. Two members spoke out against the plan.

Cantor told members that he was “tired of seeing Republicans on TV taking shots at Republicans” and urged colleagues that “we all need to rally together; we all agree that the president doesn’t have the right policies for the country,” according to the aide.

Ryan explained the CBO scoring to members and then read conservative commentator Bill Kristol’s blog post from Wednesday morning, telling members that to vote against the Boehner plan “is to choose to vote with [House minority leader] Nancy Pelosi.”

Then, McCarthy stood up and gave an inspirational speech to members, telling them that “we need to stick together as a team.”

But a vote on the plan, set to take place as early as Thursday, is still likely to be a cliffhanger. Boehner can afford to lose only about two dozen fellow Republicans before he would need Democrats in order to get his plan over the finish line. And some House Republicans remained undecided.

“I don’t want to vote for any increase in the debt ceiling unless we’ve done everything in our power to get a balanced budget amendment to the Constitution to the Senate and to the states,” former House GOP Conference chairman Mike Pence (R-Ind.) said on Wednesday, adding that he was not yet persuaded to back the GOP plan.

Rep. Trent Franks (R-Ariz.), who said Tuesday night that he was undecided, also declined on Wednesday to say how he planned to vote.

“I think this means that they have to do some rewriting,” Franks said of Tuesday’s CBO report. “I don’t think it’s a cataclysmic issue. I think it just shows the speaker is doing his best to keep his word.”

Rep. Bill Huizenga (R-Mich.), a freshman, also said he remained undecided. “I’ve got a constitutional responsibility to make a good, sound judgment,” he said. “I’m trying to make sure that I’m hearing from all sides.”

Franks also said there was “a lot of levity” at Wednesday’s meeting and that some members made remarks that were “fundamentally hysterical.”

“Sometimes, in the most excruciating moments, levity has a way of reminding us how human we all are and that we’re all trying to do the best we can,” Franks said.