Former Labour Prime Minister Gordon Brown yesterday slammed the plan submitted by the SNP to the Smith Commission on devolution, saying it “adds up to separation by another route.”

Mr Brown said SNP deputy leader Nicola Sturgeon’s proposal to devolve responsibilities except for defence and foreign affairs was incompatible with staying in the UK.

“The SNP plan for fiscal autonomy would mean no transfers of resources within the UK, ending UK pensions, ending UK help for Scots when unemployed, ending UK support for Scottish health and education — all of which Scots voted to keep,” Mr Brown said.

“It would also end the Barnett formula to which all pro-devolution parties have committed.

“Their plan adds up to separation by another route.”

Mr Brown urged Labour, the Conservatives and the Liberal Democrats to unite round his plan to make the Scottish Parliament responsible for raising more than half of its own revenue.

Scottish Labour wants powers which would allow the Scottish government to raise 40 per cent of its own budget.

Mr Brown backed the Labour proposal to put three-quarters of basic-rate income tax in Scotland under the control of the Scottish Parliament, but has gone further by proposing the assignment of 50 per cent of VAT revenues, totalling £5.5 billion.

Under the Brown plan, Holyrood would be responsible for raising 54 per cent of its own revenue, quadrupling the figure from the £4bn it currently raises to £18bn in 2016.

He said the Tories “have still to support about half of the powers Labour proposes to devolve,” including powers relating to employment, borrowing for infrastructure investment, rail services, the Crown estates and the enforcement of UK health and safety regulations and equalities legislation.