A study of the Government’s proposals for changing Freedom of Information legislation has lambasted the plans as "financially flawed and politically incoherent".

The idea - to reduce the number of freedom of information requests and save time and money spent on them – would cost £12m to bring in, with annual costs likely to wipe out savings achieved, according to analysis from the charity Public Concern at Work.

Guy Dehn, the charity's director, said: "The Government needs to go back to the drawing board and carry out a proper cost-benefit analysis."

Planned changes to the Freedom of Information and Data Protection Regulations 2007 could boost the number of requests rejected by local and public authorities purely on cost grounds before they are even looked at.

Under the draft regulations the Government is proposing that the time officials spend reading information and thinking about it should be calculated separately. Cost limits of £450 for local government and £600 for central bodies could be reached more quickly under new ways of operating, which means many requests might not even be considered.

Public Concern at Work also maintains that past applications which have saved large sums of public money will, under the proposals, now be blocked because they cost too much.

Using figures published by the Government which suggest that it costs officials between £1 and £2 to read a single page, the charity calculates that it will cost £7.2m for one official in each of the 100,000 public bodies to read the new rules and guidance restricting FOI requests and a further £5m for them to think about them.

The charity warned that if media organisations followed the Government's example and threatened to charge for the time their journalists spent reading and considering reports published by Government and other public bodies, ministers would not be able to take the high moral ground with a move that would damage the political process.

Guy added: “While it is clear that freedom of information deters waste, inefficiency and fraud across the public sector, all these benefits have been ignored in these proposals.”