The income of the richest people in Scotland has almost doubled over five years, according to Labour.
Analysis of HM Revenue & Customs data for those earning more than £150,000 a year shows that total income has grown from £3.7 billion in 2010/11 to £6.2 billion in 2014/15.
Scottish Labour are calling on the Scottish Government to support a 50p top rate of income tax.
The Government said its tax proposals will protect people on low incomes and generate extra revenue for public services.
Labour leader Kezia Dugdale said: "Austerity has been so damaging to Scotland's economy. The gap between the richest and the rest has grown.
"The richest people in Scotland are seeing their incomes balloon while the number of people for who not even a job is protection from poverty is at its highest point since the Scottish Parliament was established.
"It doesn't have to be this way. We can make different choices and build an economy that works for working class people, protects public services, and asks the richest to pay their fair share so we all benefit.
"Labour's plan for a fairer Scotland means investing more in our public services, increasing child benefit to put money back into the pockets of working class families and, stimulating economic growth through investment, not more cuts.
"The SNP's refusal to tax the richest a little more means the poorest are being hit the hardest.
"Rather than focusing on a divisive second independence referendum the SNP should use the powers of the Scottish parliament to tax the richest so we can stop the cuts and invest instead."
A Scottish Government spokeswoman said: "The Scottish Government is committed to ensuring Scotland is a country that businesses and people want to locate, live, and work in, both through preserving a competitive, progressive tax environment but also providing good quality public services.
"Where we have the powers to do so, we are making taxation fairer and more proportionate to the ability to pay, while also raising additional revenue.
"Our income tax proposals for 2017/18 and beyond will protect lower income taxpayers - but also generate extra revenue of £107 million this year to invest in public services."