Appearing before the Commons Public Administration Committee, Mr Straw also denied that the new proposals on open government were a retreat from previous Labour commitments - he said he had not "pulled to bits" Labour's 1997 white paper.

When asked if the bill was a victory for the fictional civil servant Sir Humphrey from the television programme Yes, Minister, Mr Straw said: "This is not game set and match to Sir Humphrey."

Balancing rights

Mr Straw said people were wrong to think Labour was "only in government to betray the people who elected us".

The draft proposals under pre-legislative scrutiny by the committee had been designed to balance several different rights, the right to information, privacy and confidentiality, he said.

The home secretary said the draft bill had the "balance about right but not perfect".

Richard Shepherd: The heart of the bill is missing

Tory MP Richard Shepherd criticised the bill, pointing out that it would not cover what he called "the very heart of the business of freedom of information" by failing to reveal "the information relating to how government policy is formed and how we are governed".

He added: "This to me is just like a doughnut - it is empty in the middle."

Labour MP Peter Bradley said he viewed information as the oxygen of democracy.

"It strikes me that you view it as the carbon dioxide of democracy from which we should all be protected least we inhale it too freely," he told the home secretary.

Mr Straw said he remained open to suggestions on ways to improve the bill and hinted the portion of the proposals exempting the investigation of road and rail accidents from disclosure may be changed.

He also promised open government legislation will be passed before the next general election.

Information campaign

The government is being called on to amend the bill by a group of 23 organisations backed by the Campaign for Freedom of Information and Charter88.

At the campaign launch on Monday, Labour MP Mark Fisher warned the government to expect backbench opposition to the bill should it enter Parliament unchanged.

The campaign to change the bill is also being backed by the Consumers' Association, Liberty, Friends of the Earth, Greenpeace and the National Union of Journalists as well as some Tory, Labour and Liberal Democrat MPs.

Open government survey

The home secretary's appearance before the committee coincides with an ICM survey for The Guardian newspaper, which suggests that 40% of the public strongly back the idea of new laws giving access to official information.

The survey also says that 72% support the principle that all government information should be disclosed unless disclosure would prove harmful.

Over 80% of the public are in favour of disclosing information gathered as part of police investigations, or official inquiries into road, rail and air accidents.

Disclosing such information is not part of Labour's current plans.