He has stepped in to block the release of minutes from a cabinet meeting in 1997 on devolution saying that he believes their disclosure would put the convention of collective cabinet responsibility at "serious risk of harm". It follows the justice secretary's controversial decision to use the same power in February to block the release of minutes relating to the Iraq war. From BBC News:

The minutes in question this time are from meetings of a committee chaired by then-Lord Chancellor Lord Irvine of Lairg, which gathered in secret 15 times between May and July 1997.

Its remit was to promote legislation relating to the devolution of power to Scotland, Wales and the English regions.The justice secretary said the decisionto use his veto "was not taken lightly". "Whilst the convention of collective cabinet responsibility is only one part of the public interest test, in my view disclosure of the information in this case would put the convention at serious risk of harm," he said.

This was "an exceptional case where release would be... detrimental to the effective operation of cabinet government", he added.

Information Commissioner Christopher Graham had previously ruled that the Cabinet Office should release the minutes, but the government chose to challenge that decision.

The matter was due to come before an information tribunal next year, but ahead of that Mr Straw stepped in to use his veto.

A statement from Mr Graham said: "The commissioner is concerned that the government may routinely use the veto whenever he orders the disclosure of the minutes of cabinet proceedings, irrespective of the subject matter or age of the information.

"A full hearing was due to take place on 25 January 2010 and the commissioner regrets that the tribunal's role has been disregarded at this stage."

So much for open and transparent government, eh? But I wonder what it is that Straw's so determined to hide. If Tony Blair was prepared to call the Scottish Parliament a "parish council" to the nation's press what might Labour grandees have been saying behind the closed doors of Number 10?