The draft law was submitted to the State Duma by the government and will give individuals an opportunity to declare revenues they have not paid taxes on through a simplified procedure and then make "declaration payment" worth 13% of the declared sum, which is the flat rate of income tax in Russia.
With 226 votes needed, the move was backed by 355 deputies, with 60 against and one abstention.
In line with the draft law, individuals will have time until April 2007 to declare revenues they received before January 1, 2005. No restrictions are planned on the minimum or maximum size of declared sums.
Andrei Makarov, the deputy chairman of the Duma's budget and taxes committee, said the body backed the bill as an idea to draw a line during the development of tax legislation, but criticized the government-submitted version and said it should be amended in the crucial second reading.
"People should know that if they announce their revenues, nothing threatens them in our country," he said, adding that the amnesty's aim was to allow people to be certain that they would not face tax-related charges after they make the declaration payment.
Makarov said the amnesty would be a failure if people feared prosecution for previously unpaid taxes.
Vladimir Zhirinovsky, a deputy speaker of the Duma and controversial leader of Liberal Democrats, also supported the idea. "Every effort should be made to hold the amnesty as soon as possible," he said.
A deputy from the Communists' faction, Viktor Tyulkin, was critical of the bill. "The amnesty will touch upon those who were earlier called thieves," he said. "We are against this law as the issue is about money stolen from the nation's pocket."
Pavel Voronin, a member of pro-presidential United Russia, said the amnesty would increase trust in Russia's authorities. "The middle class, not billionaires, will declare their incomes," he said.