Ministers faced the threat of industrial action last night following the disclosure that 180 quangos may be abolished and another 124 are likely to be merged in next month's spending review.
The planned cuts would lead to thousands of job losses as organisations as diverse as the General Teaching Council, the Health Protection Agency and the Herbal Medicines Advisory Council are scrapped. The leaked hitlist obtained by the BBC also suggested that 56 quangos are to undergo "substantial reform", while 282 would survive the cull. The future of another 100 bodies, including the tourism groups Visit Britain and Visit England, was yet to be decided when the Cabinet Office document was compiled four weeks ago.
Ministers suggested the list was out of date, but their attempt to play down the leak failed to satisfy unions and the bodies targeted for the axe.
Organisations facing abolition are drawn from all sectors of public life. They include the Commission for Rural Communities, the School Food Trust and the Sustainable Development Commission.
The Olympic Park Legacy Company, which is in charge of planning for the use of the east London site after the 2012 Games end, and Human Fertilisation and Embryology Authority, which regulates fertility clinics, are also due to be shut down.
The watchdogs Postcom and Ofcom are pencilled in to be merged, as are UK Sport and Sport England and the Gambling Commission and National Lottery Commission. Bodies whose future is yet to be decided include the Equality and Human Rights Commission, the British Council, the Environment Agency and the Design Council.
There are also question marks over the survival of the Student Loans Company, the UK Atomic Energy Agency and the Environment Agency, according to the document.
Unions reacted in horror over the scale of the threatened cuts. The Public and Commercial Services Union said it would consider industrial action to defend thousands of jobs that were at risk.
Dai Hudd, deputy general secretary of the Prospect union, said: "For staff whose jobs are being cut, whose pay has been frozen, whose redundancy compensation is being halved and whose pensions are next for the axe, this treatment is not just unfair, it is immoral."
Sir Ian Magee, the author of a report on quangos for the Institute for Government, warned that closing them down might not save much money in the short term. "While some bodies are well past their sell-by date, others perform important public functions: reshaping the landscapes of government needs to be more than a numbers game," he said.
Baroness Deech, a former chairwoman of the Human Fertilisation and Embryology Authority, attacked the decision to close an organisation that deals with "very important medical matters". She said: "It only costs £5m and it is not taxpayers' money. Most of the money comes from the patients."
Eric Pickles, the Communities and Local Government Secretary, said: "We did say we were going to reduce the number of quangos. We will be making an announcement in due course. It's a bit dated, that document. I think things may have moved on."
The Cabinet Office announced that Sir Gus O'Donnell, the Cabinet Secretary, had ordered an inquiry into the leak of the document. A spokeswoman added: "We deeply regret any extra uncertainty for employees this irresponsible leak has caused."
Bodies under threat
A group of scientists, veterinary surgeons and animal conservation experts who advise on conditions in zoos. It recently produced a report on elephant husbandry.
Advisory Committee on Historic Wreck Sites
Advises the Culture Secretary on the historic and archaeological significance of shipwreck sites around the UK coast and recommends the extent of access to be granted to dive teams.
Established in 2002, it brings together prominent members of Britain's Caribbean community to advise the Government on improving relations with the region.
Five-year-old quango set up to boost numbers of people taking to two wheels. Its flagship 'Bikeability' scheme, formerly known as the Cycling Proficiency Test, teaches pedalling skills to young people.
Committee on Medical Aspects of Air Pollutants
A panel of scientists and medical experts who advise the Government on the toxicity of air pollutants and their potential damage to public health.
National Tenants Voice
Only launched this year with an initial budget of £1.5m, it was designed to give social housing tenants a platform from which they could influence national housing policy.