A leading union has called for an independent inquiry into the privatisation of public services after a new poll revealed "widespread concern" over the impact on workers.
Unison pressed the Government to take action, saying that most people did not trust private firms to run health, education and other services.
A survey of more than 2,000 adults showed that 55% believed that the quality of public services was worse under privatisation.
Four out of five Conservative voters and around three-quarters of Labour and Liberal Democrat supporters said they would back increased scrutiny of Government spending on private contracts. Unison said a wide-ranging inquiry should be launched, taking evidence from all public service providers.
Dave Prentis, the union's general secretary, speaking ahead of the annual TUC conference in Brighton, said: "What we need now is an urgent inquiry into privatisation - the companies that provide public services, their employment practices, the quality of services they provide, as well as the profits they make at taxpayers' expense."
He added: "Our poll also shows just how concerned the public are about privatisation, and that lack of trust in private companies to deliver on their contracts is evenly spread amongst voters of all the major political parties. There is a fundamental lack of trust in the ability of private companies to run public services, and a strong belief that service quality suffers when private companies take over."
In contrast to the union's poll, a survey commissioned by the right-of-centre Policy Exchange think-tank suggested a majority (60%) of people who expressed a view - including 53% of public sector workers - backed private takeovers of poor-performing services.
Only 40% in the YouGov poll said public services could best be improved by keeping existing providers but bringing in new management and performance targets - though that figure rose to 56% among Labour voters.
Of those who expressed a preference, Policy Exchange said, one in five people cannot access a good local school, one in seven said there was no decent GP surgery in their area and almost one in three (31%) said they could not see a good local NHS dentist.
Sean Worth, a former Tory Downing Street adviser who now runs the think tank's public services section, said: "Tony Blair tried to reform public services but ran up against too many political roadblocks. This Government has the opportunity to finish the job."