It is likely the Kremlin will have to "increase domestic taxes and debt" to fund its planned expenditure, according to the UK defence ministry.
In its latest intelligence update, the ministry said it was "unlikely" Russia's planned revenue target for 2024 would be met as laid out in its budget plan and the government would need to consider other policy measures.
Plans to increase expenditure by 26% this year meant it was likely "the government will need to reduce its contributions to the National Wealth Fund and increase domestic taxes and debt to fund its planned expenditure", it said.
This would have "adverse effects" on the economy.
The National Wealth Fund is used to fund the long-term economic welfare of Russians but it is increasingly being used to fund the war in Ukraine.
