"There are huge steps back from the White Paper and considerable weaknesses in the Bill," said one Labour MP.
They are particularly upset that Jack Straw, the Home Secretary, has replaced a clause which would allow disclosure of information unless it caused "substantial harm" to a wider exclusion where it would "prejudice" the public interest. MPs fear it will be used by the police, government bodies, or public services to stop disclosure.
Mr Straw was to have unveiled the draft Bill in the Commons today but that has been postponed until next week to allow more time for the debate on welfare reforms, on which Labour MPs are threatening to vote against the Government.
Mr Straw is planning a robust defence of the Bill, insisting it is a radical step forward and will lead to more disclosure of information, which will affect the public in all sorts of ways. For example, parents whose children have been refused a place at school will have to be told who took the decision and why.
The Bill will be extended to cover the police, following the recommendations of the Macpherson inquiry into the murder of the black teenager Stephen Lawrence. If the proposals had been in place when Stephen was murdered his parents would have been able to demand to know how many officers were assigned to the case, alerting them to any failings in the inquiry earlier.
Some aspects of the police's role will be exempt, to avoid criminals obtaining information about informants. MI6 and MI5 will also be exempt but councils and public bodies will be covered, with privatised industries, such as British Telecom and British Gas.