By Martin Rosenbaum BBC News

Mr Prescott's committee role has been stressed

The Cabinet Office has refused to say how often the Cabinet committees chaired by John Prescott have met.

It followed a freedom of information request from the BBC.

Releasing details would make ministers "less likely to make use of the Cabinet committee system and... significantly undermine its effectiveness", it said.

Mr Prescott's role in chairing nine Cabinet committees has been stressed when questions have been raised about the deputy prime minister's workload.

Those workload questions followed the ministerial reshuffle in May which saw him lose his own department.

The Cabinet committees Mr Prescott currently chairs include those on domestic affairs and local and regional government, as well as single issues such as animal rights extremism and the Post Office network.

'Erode space'

But the government will not say how often Mr Prescott has actually had the task of chairing any of these meetings.

In dismissing the request, a Cabinet Office official wrote to the BBC: "If ministers and officials suspected that once a decision was reached, information pertaining to the process by which they reached that point was to be released (such as the timing and sequencing of meetings), they might be less willing to engage in full and frank discussion of the available options."

The official added: "We consider that disclosure of the information you requested would erode the space within which policy is developed, including the convention of ministerial collective responsibility for government policy."

Following the terror alert last week, the Home Secretary John Reid announced he had chaired meetings of Cobra, the government's emergency response committee.