Donald Trump has issued an ultimatum to Republicans in the House, telling them to get behind his proposed overhaul of Obamacare or he will leave his predecessor's healthcare legislation in place.

The US President faces a vote in the House later.

Some Republicans are opposed to Mr Trump's proposed overhaul because they say it doesn't go far enough in repealing Obamacare.

Moderate Republicans believe it could leave millions of Americans without coverage.

The showdown is the first key test of Mr Trump's presidency and a huge gamble for him, given that it was not clear as of Thursday night whether he had the backing necessary to win approval.


A vote had been scheduled for Thursday but it had to be postponed because a rebellion by conservatives and moderates would have doomed the measure.

The Speaker of the House of Representatives Paul Ryan has now scheduled a vote on the President's American Healthcare Act on Friday.

Image: Protesters gather outside the Capitol Building

"We have been promising the American people that we will repeal and replace this broken law because it's collapsing and it's failing families, and tomorrow we're proceeding" said Mr Ryan said on Thursday night.

One of Mr Trump's main election promises was to repeal and replace Obamacare, which he views as too intrusive and too expensive.

But he has struggled to get his own party representatives to support his alternative.

Mr Trump's American Healthcare Act will fail to pass if 22 or more Republicans vote against it.

Image: Donald Trump meeting truckers on Thursday morning

Republican leaders appear to be gambling that by going ahead with the vote the rebels will be forced to support the bill or risk being left with Barack Obama's healthcare legislation.

After Mr Trump's ultimatum Representative Mark Meadows said he would still vote against the bill, but did not say whether the conservative Freedom Caucus, which is opposed to it, still had enough votes to prevent it passing.

If the bill passes the House it will go to the Senate, where lawmakers are also threatening to block it.

The failure to pass the bill would be seen as a huge setback for the Trump administration at a time when it is already facing two congressional investigations and growing evidence of Trump officials caught up in surveillance by US intelligence agencies.