Finance Minister Alexei Kudrin said Russia would stick with its 13 percent flat income tax, despite speculation it would be raised as soon as more people start declaring their real incomes.

The new tax, to take effect next year, replaces a progressive system with rates ranging from 12 percent, which covers about 90 percent of the population, to 35 percent. The idea behind the flat tax was to get more people to reveal their real incomes and to spur economic growth.

Analysts have speculated the tax is designed to coax the country’s new rich into entering the tax system, and then raising the rates.

But Kudrin said Tuesday that the flat tax was here to stay. "Talk about taking more from the rich simply isn’t serious," Kudrin said.