The letter, signed by union president Alexander Shokhin, was sent to Siluanov and reported by RBC, citing two sources familiar with the document. The union argues the levy would apply retroactively and function as a turnover tax.

The Finance Ministry included the windfall tax, known by its Russian acronym NSD, in the budget package for 2027–2029. Under its plan, mining companies would surrender 30% of the additional value of raw materials generated when the average world price exceeds the 2025 level by more than 10%. For gold miners the rate would be 20%. The ministry expects the tax to raise 683 billion rubles over three years.

The union's main objection concerns how the tax is calculated. The base for the first payment in 2027 is to be calculated using prices from 2026, which has already ended, and the union argues this gives the tax retroactive force. Companies could not have accounted for such payments in advance, which the RSPP says contradicts the fundamentals of taxation.

A second objection: the NSD is calculated from the deviation of world prices and production volumes rather than from profit, so the union compares it to a turnover tax, which the government has officially renounced. Kommersant reported that the RSPP fears unprofitable enterprises would also fall under the tax.

A source at one large company told Kommersant that the approach makes it impossible to plan production and the investment cycle. The RSPP recalls that during the 2024–2025 tax reform the authorities promised to maintain fiscal stability until 2030 and to refrain from temporary, targeted withdrawals.

If an increase in the tax burden cannot be avoided, the union proposes temporarily raising the profit tax for all businesses by 0.5–1 percentage point for three years. The rate currently stands at 25%. According to the RSPP's calculation, this would give the budget from 0.5 trillion to more than 1 trillion rubles.

Analysts surveyed by RBC estimate that the bulk of the NSD burden would fall on Norilsk Nickel — 96–151 billion rubles over three years. According to Finance Ministry calculations, the company would pay more under the new tax than any other — 171 billion rubles over three years. Gold miner Polyus could pay up to 49 billion. Norilsk Nickel expressed a position similar to the RSPP's.

The RSPP also proposes exempting unprofitable companies and projects with investment agreements from the tax, and allowing amounts paid to be deducted when calculating the profit tax. The union believes the budget deficit should also be reduced through macroeconomic measures — a return to balanced interest rates and a real ruble exchange rate.

Shokhin had proposed raising the profit tax instead of one-off withdrawals before: in December 2023 he told RBC that it was better than "exotic" taxes. As Bloomberg reported, the Finance Ministry is considering a new windfall tax on a number of commodity companies and banks to cover military spending amid a growing budget deficit. According to the RSPP, under the Finance Ministry's assumptions the levy would raise about 1.1 trillion rubles over three years.