A leaked cabinet memo has revealed that the UK Government is seeking to nobble the Freedom of Information Act, a flagship piece of Blairite legislation, by making it harder for "serial requesters" to use it.

A memo by Constitutional Affairs department boss, Lord Falconer, to cabinet colleagues has been leaked to the Sunday Times. The paper reports that Falconer proposes to introduce charges to reflect the time it takes officials to read through requested files in order to ascertain they do not contain sensitive information.

There were 38,108 FOI requests in the act's first year of operation, 2005. But Falconer's memo suggest this could be reduced substantially - he says that officials estimate that a charging structure for major documents will put off at least 17% of people whose requests require a substantive response.

Currently, local authorities can charge £450 and central government departments £600 where an FOI request involves significant amounts of work in preparing a response.

Falconer also estimates that a further reduction of one-third could be made by introducing a blanket FOI charge for every request made, as currently happens in Ireland (15 euros per application).

In seeking to curtail its own legislation, by reforming it in practice, the Labour government may well be trying to outflank opposition to the FOI bill from those on the right-wing who would like to see the Act taken off the statute books altogether.