Conservatives opposed to a two-week spending bill nearly derailed a key procedural vote Monday night enabling the House to begin negotiations with the Senate over the tax bill.

The fight over how long to keep the government running after its current funding expires at 12:01 a.m. on Dec. 9 added unexpected drama to what is typically a sleepy vote on allowing the two chambers to start hammering out a compromise between their two versions of the tax overhaul.

Members of the House Freedom Caucus, a group of roughly three dozen of the House’s most conservative Republicans, initially withheld their votes on the motion, drawing a large huddle on the House floor. It later passed on a 222-192 vote, with seven Republicans opposed.

The House is expected to name later Monday night the lawmakers who will negotiate with the Senate on the tax bill.

The conservatives said they were pushing House GOP leaders to extend the government’s funding through Dec. 30, instead of Dec. 22, in a short-term spending bill on which the chamber is expected to vote on Wednesday.

Conservatives generally believe they will have more leverage in the negotiations over the next spending bill if the deadline is not right when lawmakers are trying to get home for the holidays.

“There is a whole lot more pressure to get home for Christmas than there is for New Year’s,” Rep. Mark Meadows (R., N.C.), chairman of the Freedom Caucus, told reporters after the vote.

Mr. Meadows said he spoke to House Speaker Paul Ryan (R., Wis.) during the vote and that they had a “good conversation” about the duration of the short-term spending bill. Mr. Meadows also said he spoke to President Donald Trump before the vote, but declined to give any details about their discussion.

House GOP aides said it was not clear Monday night if the duration of the spending bill would be changed. The spending bill will need 60 votes to clear the Senate, where Republicans hold only 52 seats.

Other Republicans who shared concerns about a two-week spending patch, known as a continuing resolution or CR, criticized the Freedom Caucus’s decision to flex their leverage on a procedural motion critical to advancing the tax bill.

“We’re having problems with the two-week CR vote, but trying to take out going to conference on tax reform, I don’t think that’s the best route,” said Rep. Mark Walker (R., N.C.).

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