A FURIOUS row has erupted between the SNP and Holyrood's opposition parties over efforts to secure a deal on Holyrood's new powers.

Finance Secretary John Swinney will meet Greg Hands, the Treasury Secretary on Monday in a fresh attempt to agree the "fiscal framework" underpinning the new Scotland Bill.

But in a sign of growing tensions around the talks, the SNP challenged Labour to back Mr Swinney's demands for the Scottish budget to be protect when Holyrood gains control over income tax.

Labour and the Liberal Democrats accused the Nationalists of "posturing" and "grandstanding" rather than fighting for a deal that would transfer extensive tax and welfare powers to the Scottish Parliament.

Senior SNP MSP Bruce Crawford also said "a strong case" supporting Mr Swinney's demands had been made by experts giving evidence to the Holyrood devolution committee he chairs.

The row at Holyrood came at the House of Lords economic affairs committee, which is scrutinising the Bill as part of its passage through Westminster, repeated its call for the legislation to be delayed until a deal on the fiscal framework could be reached.

Committee chairman Lord Hollick said the Government's revised timetable for the Bill, issued yesterday, would not allow peers "to have a clear idea on what they are actually voting for".

Despite lengthy negotiations, the Scottish and UK administrations have so far failed to agree a mechanism from reducing Scotland's funding from the Treasury when MSPs take control over income tax and other levies.

Mr Swinney is holding out for a method known as "per capita indexation" which would protect the Scottish Government's budget in the likely event that Scotland's population grows less quickly than England's.

Economists have generally agreed the mechanism is the most advantageous for Scotland, potentially worth hundreds of millions of pounds more per year than alternatives systems.

Critics, however, claim it would be unfair on English taxpayers.

The SNP reacted angrily after a Labour MSP, Lesley Brennan, refused to back the "per capita" system when it was endorsed by other members of the parliament's finance committee.

SNP MSP Mark McDonald said: "It is astonishing that given the choice Labour MSPs preferred to join the Tories in voting against protecting Scotland’s budget.

"Kezia Dugdale must urgently clarify her position on the fiscal framework.

"Will she back the best deal for Scotland or will she back the Tory Treasury?"

A Labour spokesman said: "This is pathetic.

"We've been clear all along we want the best deal for Scotland and to secure the powers that Scotland needs.

"It's the SNP's job to come back from the negotiations with both."

"These new powers give Scotland the chance to do things differently."

Scottish LibDem leader Willie Rennie said: "We need to see maturity from all sides if we are going to secure a deal."