The SNP would team up with Labour to hike tax for the highest earners.
Both depute leader Stewart Hosie and Deputy First Minister John Swinney said the party would sign up to their rival’s plans at Westminster to bring the top rate of income tax back to 50p for those earning more than £150,000.
Dundee East MP Mr Hosie, also the party’s Treasury spokesman, said he moved a vote in the House of Commons to stop the reduction, which every SNP MP voted for.
He added: “Labour did not. So let there be no doubt.
“We would not have cut the 50p tax rate for the very highest earners during a recession.
“We still think those with the very broadest shoulders should bear a slightly larger share of the burden.
“In the next parliament, SNP MPs will support the re-introduction of the 50p tax rate for the very wealthiest in our society.”
It comes after Alex Salmond said on television last week that the party had no plans for tax rises if they are in a position to influence the UK Government, although he did highlight his opposition to the lower rate during the interview.
Mr Swinney stressed the importance of “fairness” being extended to the tax system.
Scottish Conservative enterprise spokesman Murdo Fraser said: “This is an anti-business move which would harm job and wealth creation in Scotland.
“It has been shown that when the upper tax rate is cut, collection actually increases. This is more evidence that both the SNP and Labour are determined to drag Scotland dangerously to the left.”