The Republican-led US House of Representatives on Monday adopted a package of internal rules that give rightwing hardliners more leverage over the chamber’s newly elected Republican speaker, Kevin McCarthy.

Lawmakers voted 220-213 for the legislation, with only one Republican voting against. All 212 Democrats voted against the rules package, saying it was full of concessions to the right wing of the Republican party.

The rules package, which will govern House operations over the next two years, represented an early test of McCarthy’s ability to keep his caucus together, after he suffered the humiliation of 14 failed ballots last week at the hands of 20 hardliners before finally being elected speaker on Saturday.

The legislation includes key concessions that hardliners sought and McCarthy agreed to in his quest for the speaker’s gavel. The changes include allowing a single lawmaker to call for his removal at any time. Other changes would place new restrictions on federal spending, potentially limiting McCarthy’s ability to negotiate government funding packages with President Joe Biden, whose fellow Democrats control the Senate.

Democrats denounced the legislation as a rules package for “Maga extremists” that would favor wealthy corporations over workers, undermine congressional ethics standards and lead to further restrictions on abortion services. “These rules are not a serious attempt at governing. They’re essentially a ransom note to America from the extreme right,” Representative Jim McGovern said.

McCarthy was hard at work on Capitol Hill on Monday prior to the House going into session trying to head off any such revolt and ensure a smooth passage for the rules package later in the day. He can only afford to lose a handful votes from his party in the House to avoid defeat on any measure.

A clutch of establishment Republicans had indicated on Sunday they might withhold their support for the new rules package unless more details of McCarthy’s concessions made to the right are revealed, such as promising chairmanships of powerful committees that longer-established and more moderate members have been eyeing.

Pressure groups on Monday stepped in to make clear there will be consequences if the first vote of McCarthy’s speakership turns into a standoff.

On Friday, hours before McCarthy formally was elected to the speakership, Texas’s Tony Gonzales said he would oppose the rules package, reportedly over McCarthy’s willingness to cut spending to the defense department.

That prompted the conservative group FreedomWorks on Monday to signal that Gonzales should be frozen out if he rebels.

The South Carolina moderate Republican Nancy Mace on Monday said she was “on the fence”.

Speaking to CBS News on Sunday, Mace said of the fringe members who almost sank McCarthy’s speakership bid last week: “My question really is today: what backroom deals did they try to cut, and did they get those?”

She added: “We don’t know what they got, we haven’t seen it. We don’t have any idea what … gentleman’s handshakes were made. And it does give me a little bit of heartburn because that’s not what we ran on.”

The package itself was published on Friday evening, and includes a measure to allow a single member to force a “motion to vacate” the speakership, already weakening McCarthy’s position, and a key demand of the holdout conservatives.

It also includes reinstating a provision to allow lawmakers to propose amendments to appropriations bills, adds a 72-hour window for members to read bills before they vote, and a commitment to vote on legislation on term limits for members of Congress.