A new poll has revealed that only around a quarter of people are in favour of GPs using private firms to offer NHS services - one of the key sections of the Government's health reforms.
Around half - including 56% of Liberal Democrat voters - were opposed to the plans, according to a survey of nearly 2,000 adults for public sector union Unison.
The results were timed to coincide with the second reading of the Health and Social Care Bill, which seems certain to draw strong criticism from unions.
According to Unison, the YouGov survey revealed that just 46% of Conservative voters were in favour of private companies providing NHS services, while 22% said they "didn't know".
The poll also discovered that around half of those questioned were against GPs employing private management groups as part of the move to hand over £80 billion of the NHS budget to GPs.
Unison general secretary Dave Prentis said: "This Bill is heading for trouble. The YouGov poll shows a clear split between Lib Dem and Tory supporters. There is very weak support from Tory voters and clear opposition from Lib Dems.
"The fact is there is very little support for this Bill from anywhere. Many GPs are opposed to it, as are patients, NHS staff, clinicians, charities, think tanks, MPs and unions. The Government's vanity project is undemocratic, unaffordable and unnecessary."