The Liberal Democrats have made a dramatic intervention in the Calman process, asking for it to be re-opened so that the power of the UK Treasury can be challenged.

The Liberal Democrats have made a dramatic intervention in the Calman process, asking for it to be re-opened so that the power of the UK Treasury can be challenged.

Risking a break with Labour and the Scottish Conservatives in the joint Calman enterprise, Tavish Scott claims that rows between the Treasury and the rest of the UK have reached the point where a new Finance Commission should be established to police the disputes.

The leader of the Scottish Liberal Democrats is calling for a Finance Commission, working between London and Edinburgh.

He will write today to Sir Kenneth Calman's devolution commission asking to submit fresh evidence. "I want him to widen his work. I want to see him make tough new recommendations that take judgments of financial matters out of the single hand of the Treasury," he will say in a speech today.

Mr Scott will add: "The current method has failed on attendance allowance, council tax benefit, new prisons, police pensions and urban regeneration.

"We need a full Finance Commission that works for London, Edinburgh, Cardiff and Belfast.

Mr Scott also raised questions about the impact of the Bradford & Bingley deal, saying this "may have an impact on the public finances of Scotland if even more flexibility is given away to support more failing banks."