The warning comes as the Scottish Parliament prepares to vote for the first time to set new rates of income tax, following the successful implementation of the new Scotland Act.
The SNP Government - under pressure from the Greens - has decided to reject a plan to lift middle earners out of the higher rate of tax, as proposed elsewhere in the UK.
It will instead freeze the rate - dragging police officers, senior teachers and nurses into paying it.
The Scottish Conservatives will today step up their call for the SNP Government to prioritise economic growth by setting competitive tax rates no higher than the rest of the UK.
Scottish Conservative shadow economy secretary Dean Lockhart said:
"Over the last 18 months, Scotland’s growth rate has been around a third of that for the UK - with the result that employment is now falling in Scotland.
"The SNP's plans to set tax rates higher than the rest of the UK will only worsen this growing divide we are seeing, deterring investment and reducing new jobs.
"Our message to the SNP today is clear: it needs to mind the gap. Higher taxes in Scotland means lower growth, which will deliver less cash for government to spend on our vital public services."
"Derek Mackay's handling of the business rates crisis has shown that this Scottish Government simply does not understand business and the economy.
"It is must start to listen to job creators who need a Government which goes for growth, not one which punishes aspiration."