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Republicans in the House of Representatives unveiled their long-awaited draft healthcare bill on Monday night, amid hopes this was the first step on a road to keeping a key election promise.

Replacing the Affordable Care Act became a rallying cry among conservatives for years and here was the first attempt by the party to fashion an alternative.

But just 24 hours later and the mood in the party has changed, with the knives out for the American Health Care Act before it has even reached committee.

It is still a "work in progress", say Republicans who are behind the bill, but what happened within a few hours on Tuesday means that work may be harder than anyone imagined.

So what happened and when? All times eastern (-5 GMT)

Monday evening - last rites for Obamacare?

18:05 - Republican Party release their bill

19:50 - House Speaker Paul Ryan says "this unified Republican government will deliver relief and peace of mind to the millions of Americans suffering under Obamacare". Health Secretary Tom Price says he "welcomes action by the House to end this nightmare for the American people".

Image copyright AP Image caption Paul Ryan's hopes for unity look dashed

First signs of rebellion

19:50 - It emerges that four Republican senators had released a letter to Senate Majority Leader Mitch McConnell before the bill was unveiled, expressing concerns that it would limit future federal funding for Medicaid, which covers people on low incomes.

01:13 (Tuesday) - An influential group of US House Republicans said they had "major concerns" and called it "Republican welfare entitlement", according to a memo leaked to Bloomberg

10:26 (Tuesday) - Heritage Action for America: "That is bad politics and, more importantly, bad policy."

Tuesday - leadership reassurance

07:13 - An early morning tweet from the president shows he is fully endorsing the House bill, which he says is "wonderful".

Image copyright Twitter

13:55 - Health Secretary Tom Price says the legislation is a "work in progress" that represents a step in the "right direction".

15:53 - President Trump told Republican lawmakers at the White House: "There's gonna be no slowing down. There's gonna be no waiting and no more excuses."

16:42 - House Speaker Paul Ryan says: "Obamacare is collapsing... We are doing an act of mercy by repealing this law."

Media playback is unsupported on your device Media caption What's in the Republican healthcare bill?

The hour when it starts to unravel

14:36 - Conservative website Breitbart publishes a story headlined "Obamacare 2.0 guts enforcement, gives illegal aliens health care through identity fraud"

15:08 - Influential conservative writer Ann Coulter calls it a "piece of crap"

Image copyright Twitter

15:36 - Senator Rand Paul says: "We have to admit we are divided on replacement. We are united on repeal but we are divided on replacement." Earlier, he said the bill was "dead on arrival".

15:37 - Mike Lee, US Senator from Utah, says the bill was "a step in the wrong direction. And as much as anything, it's a missed opportunity."

Steadying the ship

17:40 - President Trump warns House Republicans of "bloodbath" if they can't pass healthcare legislation, says CNN

19:14 - He then cajoles Senator Rand Paul to end the dissent and rally behind the "great" health care bill.

Image copyright Twitter

Will the bill survive? Anthony Zurcher, BBC News, Washington

It seems like passing the recently unveiled Republican Obamacare replacement bill will be about as difficult as making a half-court basketball shot. From a moving car. While blindfolded.

While Republicans know they have to do something on healthcare reform given seven years of promises, when the subject moves to what to do after repeal, party cohesion falls apart. Moderates hate the bill because of its coverage cuts. Conservatives hate the bill because it preserves parts of the existing system. The only real support the bill has is of the tepid variety.

Donald Trump tweeted that the legislation is now open for "review and negotiation", but the various factions within the Republican congressional caucus will be pulling in opposite directions - and the end results could be a proposal that is left in tatters.