The US House of Representatives voted on Friday to approve a sprawling US$1.2 trillion package to fund the government, provoking an angry response from conservatives and kicking off a race against the clock in the Senate to ensure the lights stay on past a midnight deadline.

Party leaders in the upper chamber were scrambling to agree on a sped-up timeline to green-light the legislation, with just hours left to avert a shutdown of several federal agencies including defence and homeland security.

But the legislation has already been delayed by six months in a Congress which is divided almost evenly between the parties, and has been deadlocked by policy and spending disputes.

Party leaders fear the Senate may struggle to rubber-stamp the House vote before the midnight deadline, with arcane procedural rules threatening to push the action into the weekend.

The House Republicans' right flank was angered by a lack of stricter border security provisions in the package, as well as the spending figure and the elevated speed with which the deal has been negotiated.

Marjorie Taylor Greene, a hard-right ally of Donald Trump, threatened to force a vote to remove Republican House Speaker Mike Johnson, accusing him of offering too many concessions to Democrats.

She signalled in an interview ahead of the vote that she would mull filing a "motion to vacate" the speakership – the move that toppled Johnson's predecessor Kevin McCarthy as party leader last year.

The Georgia congresswoman called the funding measure "an atrocious attack on the American people" in an excoriating floor speech.

A lapse in federal funding over Saturday and Sunday would have a limited impact on government operations and would not likely be felt by the public, as long as the spigot was turned back on at the start of the working week.

A longer pause could result in thousands of public employees being sent home without pay and a vast array of government operations and services being hit, from airport security to border controls. (AFP)