Plans to change the Freedom of Information Act could put at serious risk the public's right to know what lurks in the corridors of power.

The Government's Ministry of Justice, headed by MP Jack Straw, who has a house in Minster Lovell, has three months to consider responses to proposed changes to the Act.

It claims a flood of requests was placing a "disproportionate burden on public authority resources".

Today, in a special report, the Oxford Mail examines why the Government wants to change the legislation - and looks at some of the ground-breaking stories that have been highlighted with Freedom of Information.

Plans first drawn up by the now defunct Department of Constitutional Affairs and brought forward by the Ministry of Justice aim to modify the Act, which came into force in January 2005.

The MoJ wants to calculate the reading time, consideration time and consultation time involved in all requests to estimate a total cost.

It proposes to reject those requests that would cost more than £600 for Government departments, or £450 for other organisations, to process.

At the moment, there is no specific cost ceiling.

If significant changes are made, public bodies from the county and city councils to the health authority and courts, could make it it almost impossible for information to be released.

Stories like the one in which the Mail revealed the extent to which criminals were carrying knives on the city's streets might not have seen the light of day on cost grounds.

A response to a request submitted to Oxford Magistrates' Court revealed hundreds of knives, blades, needles, syringes, spanners and batons had been confiscated at the court doors.

Det Chief Insp Andy Boyd of Oxford CID praised the Mail for uncovering and highlighting the issue and said: "I'm staggered - it's disappointing and somewhat surprising to see the amount of knives that have been handed in."

Freedom of information has been vital in helping journalists provide the public with information about issues like how the number of staff employed by Oxfordshire County Council jumped by more than 30 per cent in a decade, to how much compensation Royal Mail paid out each day to fed-up customers in the city.

Maurice Frankel, director of the Campaign for Freedom of Information said: "Requests about complex, contentious or just unfamiliar issues would be most at risk.

"The public interest in disclosure could be ignored.

"The hours needed to deal with an unwelcome request could be boosted by deliberately consulting lawyers or other specialists or ensuring meetings involved not only the officials handling the issue, but their line managers and departmental heads too.

"Meetings wouldn't actually have to take place - an estimate of their likely hours would do.

"Ministers also want to allow authorities to add up the cost of all the requests made by the same individual or organisation to an authority during any three months - and refuse them if the total is more than the £450 or £600 limit."

A response by the MoJ on changes to the Act is expected later this year.