The Health Secretary, Andrew Lansley, has signalled that he is preparing to make concessions to his controversial NHS reform programme in the face of growing opposition from doctors, unions and his own Coalition partners.
The campaign group 38 Degrees – which was instrumental in forcing the Government to drop its plans to sell off parts of Britain's forests – collected more than 80,000 signatures against the plans over the weekend.
The British Medical Association will hold an emergency meeting tomorrow to decide whether to oppose the reforms – which would hand over huge power to GPs to commission treatments for their patients.
The Deputy Prime Minister, Nick Clegg, spent the weekend firefighting criticism from activists in his own party at the Liberal Democrat Spring Conference, where members voted overwhelmingly for ministers to re-consider key aspects of the proposals.
Mr Lansley yesterday suggested that the reforms were not set in stone and could change. Questioned about the scale of opposition from the Conservatives' coalition partners, he said: "Our proposals are always under review.
"As you put a bill through parliament you look carefully at how the legislation delivers in the context of the reforms that we set out. We've already made changes. We are not sitting there thinking we must know the answers and nothing can change."
Privately, senior Lib Dem figures fear that the health reforms could be disastrous to the party's reputation and electoral prospects if they are mishandled.
"This could be worse for us than tuition fees," said one source.
Lib Dem members voted to demand rules that would prevent private providers from coming in to "cherry pick" the most profitable NHS services, and also to ensure that elected local authority representatives are involved in commissioning decisions.
The party leadership said it would "listen" to activists' views.
But Evan Harris, a former party health spokesman, said this was not acceptable. "Listening is not good enough," he said. "We want major changes in policy and significant changes to the bill."
In his conference speech Mr Clegg repeated his pledge that the NHS would never be privatised. "No government of which I am part will tamper with the essential contract at the heart of the NHS: to care collectively for each other as fellow citizens," he said.
Members of 38 Degrees voted to make "Saving the NHS" their top priority. The online group's executive director, David Babbs, said: "38 Degrees members have proved with the forest sell-off that when we come together in big numbers, it's possible to make the government think again."
In addition, representatives of the 140,000-member British Medical Association will hear demands from doctors that the Government hold a public referendum on the reforms and withdraw its Health and Social Care Bill "if there is not a clear mandate of support".
Doctors are concerned that the measures would increase competition and encourage privatisation, and their scepticism is matched by that of think-tanks, the health select committee, medical journals and even David Cameron's cardiologist brother-in-law.
Robust exchanges over the best way forward are expected at tomorrow's meeting, which will be attended by 350 representatives of consultants, GPs and junior doctors.
The BMA will also debate a motion of no confidence in Mr Lansley.