Jack Straw said he had not taken the decision lightly
The justice secretary has blocked the release of minutes of a 1997 cabinet committee meeting on devolution.
Jack Straw said he believed disclosure would put the convention of collective cabinet responsibility for decisions "at serious risk of harm".
The UK's information commissioner said he would "carefully consider" Mr Straw's reasons for using his veto.
The only other time he has used it was to block the release of cabinet minutes relating to the Iraq War.
That decision in February - relating to discussions about the legality of the war - was again to protect the convention of collective responsibility.
The principle is that once a decision is made by the cabinet, all ministers are bound by it and must support it publicly.
If they cannot do so, they are expected to resign their ministerial post.
'Not taken lightly'
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 decision to 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."
Liberal Democrat justice spokesman David Howarth said it was an "insult" that Mr Straw had not waited for the tribunal.
"This completely undermines Labour's claims to be committed to open government," he said. "The veto is clearly a threat to freedom of information and should be abolished."