First Minister John Swinney has been urged to rule out a “North East tax” after documents revealed proposals previously being considered by the SNP.

As the SNP prepares to set out its General Election manifesto on Wednesday, the Scottish Conservatives said the party must “come clean” about plans for a tax on energy businesses and changes to non-domestic rates.

Documents obtained by the Tories using freedom of information laws show a policy consideration in 2022-23 discussed “immediately” exploring whether devolved tax powers could be used to target windfall profits.

John Swinney speaking with a Saltire flag as backdrop
Scottish First Minister and SNP leader John Swinney will set out his party’s manifesto on Wednesday (Jane Barlow/PA)

It went on to discuss whether non-domestic rates – business taxes – could be increased to raise money.

However, much of the document was redacted so it is unclear whether any costings were included in the proposals – and it did not become Scottish Government policy.

Andrew Bowie, Scottish Tory candidate for West Aberdeenshire and Kincardine, said any such tax would be “damaging” for businesses in the region.

He said: “These new documents reveal the SNP were secretly planning a huge tax hike on Scottish businesses.

“The SNP’s North East tax would have put jobs at risk and hammered the local energy sector.

“John Swinney must rule out ever introducing such a damaging new tax.

“He must also come clean about the scale of these plans because SNP secrecy has limited how much we know about this worrying proposal.

“There are so many redactions that we don’t know if the nationalists were planning to try and raise millions or billions from businesses.

“People in the north east deserve to hear straight answers from the SNP. Will they try to introduce this north east tax after the election?”

A Scottish Government spokesperson said: “Scottish ministers called on the UK Government to introduce an enhanced windfall profits tax, which it duly did in November 2022.

“Scottish ministers remain supportive of a windfall profits tax across all sectors of the economy where excess profits emerge, not just energy companies that are disproportionately based in Scotland.

“The Scottish Government does not agree that the UK Government should have extended the energy profits levy as they did in their Budget in March.

“This disproportionality targets Scotland and risks undermining the very investment we need to unlock a just transition to net zero.”