The Republican-led US House of Representatives has adopted a package of internal rules that give right-wing hardliners more leverage over the chamber's newly elected Republican Speaker, Kevin McCarthy.
Lawmakers on Monday 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.
Republicans have a narrow majority of 222-212 in the House after winning fewer seats than expected in November's midterm elections. This has amplified the hardliners' power and raised questions about how the divided Congress will function.
Lawmakers face critical tasks in the year ahead including addressing the federal government's $US31.4 trillion ($A45.5 trillion) debt limit. Failure to do that, or even a long stand-off, would shake the global economy.
Other changes include a 72-hour waiting period between when a bill is introduced and when it can get a vote, a cap on government spending at 2022 levels and the creation of a committee to investigate the Justice Department.