The SNP was accused of neglecting jobs in favour of separation
The latest EY Scottish Item Club report said the country's economy showing signs of slowing faster than the rest of the UK as consumer spending fades and firms remain reluctant to invest.
It predicted "below-par" GDP growth of 0.9 per cent in 2017 – half of that expected for the UK and said the threat of another independence referendum adds a "potentially corrosive layer of uncertainty".
Economists suggested the retail sector would be worst hit by "mounting pressure" on consumers.
Employment in Scotland is also forecast to continue to fall this year.
In 2017, it is expected to drop by 0.1 per cent, followed by further decreases of 0.5 per cent and 0.3 per cent in 2018 and 2019 respectively.
It follows offical figures last month showing that Scotland is teetering on the brink of recession after going backwards in the final three months of 2016, at a time when the UK economy grew.
Scottish Tory economy spokesman Dean Lockhart said: “This is another damning report that shows just how much harm has been caused by the SNP’s handling of our economy.
Economists suggested the retail sector would be worst hit by 'mounting pressure' on consumers
“While the rest of the UK economy grows we are on the verge of a recession, and these figures confirm that we are stuck in the ‘slow lane’.
“With the SNP focused on independence they’ve neglected jobs, businesses and Scotland’s economy."
The item club said Scottish households were "likely to endure a fall in real incomes" this year as a result in part of rising inflation and "weak" labour market conditions.
Scottish growth will slow a little in 2018 to 0.7 per cent before gradually accelerating to around 1.4 per cent by the end of the decade.
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Economy Secretary Keith Brown insisted 'the foundations of Scotland's economy are strong'
But it predicts that throughout this period, the Scottish economy will grow more slowly than the UK.
Dougie Adams, senior economic advisor to the EY Scottish Item Club, described the Scottish economy as being "stuck in the slow lane".
The report described productivity as "disappointing" since the 2008 financial crash while Brexit could add to a "risk productivity growth regresses again".
It added: "Finally, the prospect of a second referendum on Scotland’s constitutional position hangs in the air, adding an additional and potentially corrosive layer of uncertainty for many Scottish businesses."
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SNP leader Nicola Sturgeon stops for an ice cream after making an election campaign visit to Scottish Gas HQ in Granton, Edinburgh
Economy Secretary Keith Brown insisted "the foundations of Scotland's economy are strong".
He added: "Unemployment is falling and we are seeing early signs that the situation is improving for North Sea operators.
"This report also comes after the 2017 EY Scotland Attractiveness Survey confirmed 2016 was a record-breaking year for foreign direct investment into Scotland.
"For the second year in a row we have attracted more projects than ever before and Scotland has been the top UK region outside London in every one of the past five years."