TAX rises for Scots are “inevitable”, former SNP cabinet minister Kenny MacAskill has said.

The former Justice Secretary said it was now “simply a question of how much and upon whom they will fall”, and forecast the middle classes were likeliest to be hit.

But he also warned it was hard to see how a tax rise could “shore up the current services, never mind allow for expansion of new ones”.

He suggested “a strategic retreat” from some areas was needed through cuts or reform.

Nicola Sturgeon recently called for a cross-party debate on more “progressive” taxes in 2018/19, signalling that all rates of income tax could potentially change.

SNP ministers are also considering whether extra tax bands could be created.

Scots are currently taxed at 20p in the pound above the £11,500 allowance, then at 40p for earnings above £43,000, with top earners paying 45p for any salary above £150,000.

In a newspaper article, Mr MacAskill, who quit cabinet when Ms Sturgeon became First Minister in late 2014, suggested middle income taxpayers were likely to be hit most.

He said “punitive taxes on the rich, even if popular, won’t work and could even be counterproductive”.

Referring to the First Minister, he said: “It seems that she’s setting the scene for middle earners to pay more. That’s understandable and right.

“The Scottish middle class can’t expect the universal services they mainly benefit from without paying for them.

“In all likelihood it will be a re-run of Alex Salmond’s call in 1999 for a penny for Scotland.”

Adding 1p to all income tax bands would raise around £500m extra, but would break an SNP manifesto commitment not to raise the basic 20p rate.

Before the 2016 Holyrood election, the party insisted: “The basic rate of tax will not be increased at any point in the next Parliament if an SNP government is re-elected.”

Mr MacAskill said voter satisfaction with public services was declining, and with it people’s satisfaction with the First Minister.

He went on: “More just can’t be done with less or even the same. Until a strategic retreat is made from some areas of expenditure or savings made through reform, then the creaks and groans from overburdened and under-resourced public services will only increase.

“Yet, it’s on that that both the Scottish Government and Nicola Sturgeon will be judged.”

He said that promising new services at the SNP conference while failing to deliver on other essential services posed “a danger for her and her administration”.

He said: “Neither she nor the SNP are in control of the major issue that affects them in Brexit. They just need to await the outcome and be ready to move thereafter [on the issue of a second independence referendum].

“In the interim they need to maintain the credible and competent administration that saw them elected in the first place.

“That’s the priority and the dangers for her now lie there, not in the constitution.”

LibDem MSP Alex Cole-Hamilton said: “The SNP need to make up their mind where they stand on taxation. Last month they abstained in Parliament on a vote calling for modest increases in taxation to properly fund public services. It is time they got off the fence.”