Republican leaders in the Senate finally unveiled a draft of the healthcare legislation aimed at replacing Obamacare, but immediately hit a huge obstacle with at least four of the party’s Senators saying they would not vote for the plan in its current form.

The fate of the bill is now up in the air - not for the first time - with Democrats only needing the support of three Republicans to vote down the legislation. The Republicans hold a 52 to 48 advantage in the Senate, and can afford to lose two votes, with Vice President Mike Pence being able to beak a tie.

But passage will not be easy with members on both sides of the Senate angry about the secrecy involved in the drafting on the legislation by the Republican leadership, which meant the first thing many Senators saw of the draft bill was when it was released on Thursday morning and reservations about the content were quick to surface.

One of President Donald Trump’s main promises on the campaign trial was to repeal and replace his predecessor Barack Obama’s signature healthcare policy. He held a congratulatory press conference when a version of the bill passed through the House last month, having already been re-drafted once - but apparently later privately based the House bill as “mean”.

Mr Trump welcomed the 142-page Senate draft, saying that he wanted a health plan “with heart”. He told reporters at the White House that healthcare legislation will require “a little negotiation, but it's going to be very good.” He said he doubted Democrats would help. He later tweeted he was “very supportive” of the bill.

However, the problems run much deeper than that, with any chance of a vote on the bill - which Majority Leader Mitch McConnell wants for next week - getting smaller by the day. A draft of the bill shows that the Senate legislation is similar to the House’s American Health Care Act. The Senate bill would make major changes to the US’s healthcare system, including drastically scaling back government spending on Medicaid – a healthcare programme for the poor – and terminating the ACA’s taxes on the rich and health insurers. However, the plan would maintain Obamacare’s subsidies to help people afford individual coverage.

Faces of Obamacare: The health scheme at the centre of the shutdown Show all 3 1 /3 Faces of Obamacare: The health scheme at the centre of the shutdown Faces of Obamacare: The health scheme at the centre of the shutdown obama.jpg Martin Wolske, 49 and his family, Illinois. His son Eric, 23 (bottom right, dark hair) was recently badly injured in a motorcycle accident. Faces of Obamacare: The health scheme at the centre of the shutdown obama2.jpg Tracy Russo, 31, Washington DC Faces of Obamacare: The health scheme at the centre of the shutdown obama3.jpg Kevin McCollum, 41, and his wife Melissa, 40, Texas

“The current bill does not repeal Obamacare,” Rand Paul, one of the four Senators, along with Ron Johnson of Wisconsin, Ted Cruz of Texas and Mike Lee of Utah, who have said in a joint statement that they're “not ready to vote for this bill.”

“It does not keep our promises to the American people. I will oppose it coming to the floor in its current form, but I remain open to negotiations, “ Mr Paul said.

A number of Republicans such as Susan Collins and Maine said it was “too soon” to judge the bill until they had had a chance to read it. Veteran Senator John McCain said the draft bill was better than Obamacare in "100 ways," but like many Senators wanted to study the bill further and consult with his state's governor.

States with a large population receiving Medicare, health insurance for seniors, or Medicaid, government-subsidised insurance for low-income or disabled people, may be negatively affected by the bill in its current draft.

With a third of the Senate coming up for re-election in 2018, many will have to weigh the state-wide implications before voting for the bill.

Democratic leaders of Congress, who want the Obamacare law fixed but not abandoned, immediately attacked Senate Republicans' version.

”The president said the House bill was mean,“ said Senate Democratic leader Chuck Schumer. ”The Senate bill may be even meaner.“

Mr McConnell said Democrats chose not to help frame the bill.

”I regret that our Democratic friends made clear early on that they did not want to work with us in a serious, bipartisan way to address the Obamacare status quo. But Republicans believe we have a responsibility to act, and we are,“ Mr McConnell said.

Like the House bill, the Senate would repeal a penalty associated with the individual mandate requiring most people to have health insurance or else pay a fine. Policy experts said that would keep more young, healthy people out of the market and likely create a sicker patient pool.

The legislation would also repeal the penalty associated with the mandate that employers provide employees health insurance.

The Senate bill would provide money to stabilise the individual insurance market, allotting $15 billion per year in 2018 and 2019 and $10 billion per year in 2020 and 2021.

The Senate bill proposes defunding Planned Parenthood for a year, but abortion-related restrictions are less stringent than the House version. There is some uncertainty over whether abortion-related provisions will meet Senate rules, but those provisions could be included in another Senate bill.

Obamacare is credited with expanding health insurance to millions of Americans since its passage in 2010. Republicans say it costs too much and involves the federal government too much in healthcare. Most Republicans opposed to the draft bill say it will not reduce insurance premiums enough.

The nonpartisan Congressional Budget Office (CBO) has estimated that the House bill would kick 23 million people off their healthcare plans. The CBO is expected to weigh in on the Senate draft bill early next week.

Concerns have been raised by activist groups for months about the new healthcare legislation, with a new NBC News/Wall Street Journal poll released just before the draft of the Senate bill showing just 16 per cent of adults believe that House health care bill is a good idea, versus 48 per cent who say its a bad idea.

Protests continued on Thursday, with Capitol Hill Police forcibly removing protesters in wheelchairs from Mr McConnell’s office. ADAPT, a disability rights organisation, staged a “die-in” outside Mr McConnell’s office to protest the Medicaid cuts within the legislation, used by many disabled individuals.

Approximately 60 protesters – many of them in wheelchairs – flooded Mr McConnell’s office around 11 am on Thursday. Some made their way inside the office, lifting themselves out of their chairs to lie across the Senator’s floor.

The purpose, according to the ADAPT, was to “dramatise the deaths” they say the American Health Care Act (AHCA) will cause.

“We’re hanging out there like a ripe cherry to be plucked,” Mike Oxford, one of the protest organisers, told The Independent of the disabled community. “Not only will people lose their freedom, but people will die if they do this.”

One person being rolled out by a police officer called out, “Don't mess with my Medicaid!” Another walked out of the officer with her hands tied behind her back, followed closely by an officer. Yet another was pulled from her chair by police officers trying to remove her from the area.

Capitol Police said that the protesters were warned they would be arrested if they did not co-operate, forty-three protestors arrested and charged with crowding or obstructing, or incommoding.

The protestors came from as far away as Colorado and Kansas to rally against what they see as a threat to their freedom.

“We’re protesting the American Health Care act cutting hundreds of billions out of Medicaid to gives tax breaks to the wealthiest,” Mr Oxford said of the die-in.