LIBERAL Democrat ministers have been accused of hypocrisy after blocking the release, under Freedom of Information law (FoI), of cabinet papers showing early splits over devolution.

Despite priding themselves on pioneering FoI, the deputy prime minister Nick Clegg, Scottish Secretary Michael Moore and other senior LibDems vetoed the release by over-ruling a judgment of the UK's Information Commissioner.

The documents relate to the creation of devolution in Scotland, Wales and Northern Ireland at the outset of Tony Blair's New Labour government.

The Cabinet Office claimed the material is still so sensitive it could deepen current rows between the devolved governments and even spark new fights.

Exposing past splits could also embarrass some of those involved at the time, 12 of whom are now MPs, and 19 of whom are in the House of Lords.

Despite the objections, the Information Commissioner recently ruled there was a "strong public interest in disclosure in order to inform current and future debate on - devolution"

But Attorney General Dominic Grieve, a Conservative and the Coalition's most senior law officer, last week used the "nuclear option" under FoI law south of the Border to veto any disclosure by claiming there were "exceptional circumstances" involved.

The Sunday Herald has established the ultimate decision to use the veto was a collective one by the Coalition cabinet, taken after it had been briefed by Grieve – meaning that LibDems ministers were actively involved and supported it.

It was only the third use of the veto since FoI was introduced in 2005, and the first time that LibDem ministers have been party to it.

The two previous vetoes were both in 2009, when Labour Justice Secretary Jack Straw blocked release of cabinet papers on the Iraq War and later blocked the release of similar papers on devolution.

The latest veto covers the minutes of the Cabinet Ministerial Committee on Devolution to Scotland, Wales and the English Regions, which ran from May 1997 to June 2008.

In 2010, the Cabinet Office refused two requests for the material, prompting appeals to the UK Information Commissioner's Office (ICO). Last year, the ICO said in both cases the material should be released in the public interest. However, the veto overrides the ICO's ruling.

Grieve admitted the release of the papers "would improve the ability of the public to assess the Government's analysis, and approach to, devolution - and would inform current and future debate".

But he said the benefits were outweighed by the danger in exposing "divergent ministerial views", which would "seriously prejudice" the practice of collective cabinet responsibility, which obliges ministers to back government decisions.

In a statement of reasons, he said: "The matters discussed are manifestly not of purely historical interest and importance. Disclosure of minutes also gives rise to a real and significant risk that debates and discussions between the administrations would be prejudiced.

"A number of individuals have comments attributed to them in the minutes, including where they are not in agreement on certain policy issues."

The SNP said: "This is yet another example of the LibDems saying one thing in Holyrood and doing the exact opposite at Westminster.

"We know that Cabinet papers are not generally published, but it is hard to see how these devolution documents from the 1990s could be controversial now."

A LibDem source was dismissive of the criticism, and said it was the SNP which had the poor record on FoI.

The ICO said it regretted the veto and would now make a special report on its use to Parliament.