One of America's most senior medical officers has spoken out against Donald Trump’s plan to replace Obamacare with the American Health Care Act (AHCA).
“Despite political messaging from others at HHS, I align with the experts from [American Academy of Family Physicians, American Academy of Pediatrics and American Medical Association] in opposition to #AHCA," Andrey Ostrovsky MD wrote on Twitter.
Dr Ostrovsky has served as chief medical officer for The Center for Medicaid - a social health care program for families and individuals with limited resources - and the Children’s Health Insurance Program (CHIP) services, since October.
Mr Ostrovsky’s remarks came after Mr Trump hailed the newly proposed bill - which some have dubbed as "Trumpcare" - as “wonderful”.
The President tweeted: “Our wonderful new Healthcare Bill is now out for review and negotiation. ObamaCare is a complete and total disaster – is imploding fast!”
The proposed new system would scrap packages from the Affordable Health Care for America Act, known as Obamacare, in favour of refundable tax credits.
It would scale back the former President’s expansion of Medicaid – the largest source of funding for medical and health-related services for low income Americans.
It would also reduce funding for Planned Parenthood, a family planning organisation which provides abortion – which remains a highly contentious issue in the US, as well as enabling insurers to impose a 30 per cent surcharge on premiums for any lapses in coverage.
Lottery winners will also be barred from claiming Medicaid and the bill will also repeal a tax on indoor tanning beds.
Major medical groups have also voiced opposition to the plan, along with many members of Mr Trump's Republican Party.
In a letter addresses to the House of Representatives, the American Hospital Association (AHA) urged politicians to find ways of doing more to improve health care for the poor, elderly and disabled.
"Health care coverage is vitally important to working Americans and their families," the letter read. "We recognise this measure represents the first step in a process. It is critical that this process be thoughtful and focused on finding ways to improve our health care system, particularly for the poor, elderly and disabled.
"We ask Congress to protect our patients, and find ways to maintain coverage for as many Americans as possible. We look forward to continuing to work with the Congress and the Administration on ACA reform, but we cannot support The American Health Care Act in its current form."
Senate Minority Leader Chuck Schumer criticised the proposed cuts to Planned Parenthood, which provides millions with access to mammograms and cancer screenings as well as maternity care.
The controversial orders Donald Trump has already issued
The controversial orders Donald Trump has already issued
1/8 Trump and the media
White House Press Secretary Sean Spicer takes questions during the daily press briefing
2/8 Trump and the Trans-Pacific Partnership
Union leaders applaud US President Donald Trump for signing an executive order withdrawing the US from the Trans-Pacific Partnership negotiations during a meeting in the Roosevelt Room of the White House in Washington DC
3/8 Trump and the Mexico wall
People protest against US President Donald Trump's inauguration next to a fake wall with a Mexican national flag and a dummy representing him in Mexico City
4/8 Trump and the Mexico wall
A US Border Patrol vehicle sits waiting for illegal immigrants at a fence opening near the US-Mexico border near McAllen, Texas. The number of incoming immigrants has surged ahead of the upcoming Presidential inauguration of Donald Trump, who has pledged to build a wall along the US-Mexico border
5/8 Trump and abortion
US President Donald Trump signs an executive order as Chief of Staff Reince Priebus looks on in the Oval Office of the White House
6/8 Trump and the Dakota Access pipeline
Opponents of the Keystone XL and Dakota Access pipelines hold a rally as they protest US President Donald Trump's executive orders advancing their construction, at Columbus Circle in New York. US President Donald Trump signed executive orders reviving the construction of two controversial oil pipelines, but said the projects would be subject to renegotiation
7/8 Trump and the Dakota Access pipeline
US actress and political activist Jane Fonda attends a rally with opponents of the Keystone XL and Dakota Access pipelines as they protest US President Donald Trump's executive orders advancing their construction, at Columbus Circle in New York
8/8 Trump and 'Obamacare'
Nancy Pelosi who is the minority leader of the House of Representatives speaks beside House Democrats at an event to protect the Affordable Care Act in Los Angeles, California. The Republican-led US Senate has launched their much-anticipated effort to repeal the Affordable Care Act by passing a budget blueprint which would allow them to begin rolling back the health care reforms
Critics are also concerned that the new bill does not immediately roll back the Obama expansion of Medicaid eligibility to most poorer adults in more than 30 states, while others oppose universal healthcare provision of ideological grounds because they view insurance as any other consumer good.
Obamacare has significantly reduced the number of Americans left without health insurance since it became law in 2011.
Some have attacked it however, claiming it has increased the cost of some packages and increased the national debt.
If enough Conservatives vote against the bill, it could fail to pass through the chamber.
The Republicans hold only a slim majority in the Senate and it would require just three of them to vote against the bill to derail it if the Democrats vote in a block.