The Scottish National Party's (SNP) plan for full fiscal autonomy for Holyrood from Westminster would cost Scotland billions of pounds, Ed Miliband has warned.
The Labour leader argued that Nicola Sturgeon's party would replace the Barnett formula with a "reliance on risky and unpredictable" oil revenues.
"But that has real consequences for Scotland. Because fiscal autonomy makes it impossible for Scotland to end Tory austerity. Worse than that it would extend it," Miliband said.
The unionist MP cited data from the Scottish Government, which would mean" huge cuts" to the funding of health, education and policing.
"In total on the basis of the budget, £7.6bn ($11.3bn, €10.3bn) lost to the people of Scotland. So the SNP's proposals for fiscal autonomy would cost Scotland billions," Miliband said.
"Money that would have to come from cuts to the fundamental public services on which all the people of Scotland rely. Or from new taxes on working people."
The comments come after a poll from ICM for The Guardian showed that the SNP have a 16-point lead (43% vs 27%) over Labour in Scotland.
The survey, which comes just weeks before the general election, also put the Liberal Democrats on 6% and the Tories on 14%.
The data is bad news for the new Scottish Labour leader Jim Murphy, who was appointed to the role in December.
Miliband has ruled out a coalition between the SNP and Labour after the vote in May.
But SNP grandee Alex Salmond told the BBC's Andrew Marr show that a "vote-by-vote arrangement" would be the most likely outcome of the election.
The former first minister of Scotland also said he wanted to see a so called "progressive coalition" between the Greens, the SNP and Plaid Cymru after the election.
Labour are two points ahead of the Tories (35% vs 33%) in the national polls with the election looming.
But a poor performance north of the border could leave Miliband's party short of a majority in the House of Commons.