The House of Representatives will vote on Donald Trump's revised healthcare bill on Thursday, Republican leaders have announced, suggesting they that have secured enough support for it to pass.

The US leader, who repeatedly promised to repeal and replace Obamacare during his presidential campaign, suffered a major setback after a vote on an earlier version of the American Health Care Act was dramatically cancelled at the last minute when it failed to gain enough support from members of his own party.

Keen to score his first major legislative win since taking office in January, Mr Trump has been personally engaged in building support among fellow Republicans in the House of Representatives.

The bill, which has been vehemently opposed by the Democrats, would require 216, all Republican, votes to pass.

Congressmen Billy Long and Frank Upton are among those who have flipped their vote to 'yes'. The pair said Mr Trump has endorsed their plan to add $8bn (£6.2bn) over five years to help cover the cost for people with pre-existing illnesses.

Mr Long is a member of the House Energy and Commerce Committee, one of the the groups in charge of healthcare policy. Mr Upton, a former chairman of that committee, said that the bill is now likely to pass in the House, but added that he is not on the whip team, so he can’t know for sure.

They had previously withdrawn their support for the Obamacare repeal after the addition of the MacArthur Amendment, which would have allowed states to drop the guarantee that pre-existing conditions would be covered. The incorporation of that provision helped Republican leadership in the House gain the endorsement of the Freedom Caucus – a group of roughly three dozen conservative hardliners who demanded that the new law repeal more of Obamacare’s insurance mandates.

White House Press Secretary Sean Spicer said Vice President Mike Pence was on Capitol Hill to meet with politicians about healthcare and the rest of the president’s legislative agenda.

Meanwhile, congressional Democratic leadership said the addition of Mr Long's and Mr Upton's amendment does not actually improve the quality of the bill. House Minority Leader Nancy Pelosi called it “a very sad, deadly joke.”

“What you would need is probably about $200 billion over 10 years. What they’ve done is $8 billion over five years,” she said at a press conference outside her office in the Capitol. “If you divide that by the number of people who have a pre-existing medical condition, you get about [$200 or $300] a year.”