The number of quangos has increased since Labour came to power, it has been claimed.

According to the BBC's "Kenyon Confronts" documentary, to be screened on Wednesday, at least 23,000 people sit on 850 public bodies.

This is despite Tony Blair's 1996 pledge to "put the quango state in history's dustbin where it belongs".

The report claims that there are five times as many Labour supporters appointed to the organisations than those declaring support for the Conservatives.

There are six times as many failed Labour candidates on quangos than Tories, and twice as many Labour peers.

"They've cut down the number of quangos at national level but what they've done is create many, many more really very powerful [Scottish, Welsh and Northern Irish] bodies - the kind that we didn't really have before," said Professor Stuart Weir, an adviser to the Commons public administration select committee.

"Also at local level, there's been at least a doubling of the number of unelected bodies."

"They're not really representative of ordinary people or the public and they're not properly accountable," he added.

"They're not even open to the public. If you want to know what was happening on a quango, your chances of finding out are nil."

The programme highlights the case of science minister Lord Sainsbury.

He is involved in appointing members of the Biotechnology and Biological Sciences Council (BBSRC), which has spent £18 million on research into genetically modified crops.

Of the 15 current members, eight have associations with the pharmaceutical or biotechnology industries.

Speaking to the programme, the Labour peer defended his role.

"The members of the BBSRC are selected on the basis of their expertise...people are not excluded because they have commercial connections which have been declared," he said.

Lord Sainsbury added that he takes no part in discussions relating to GM foods.