Iran's legislators have adopted a $279 billion budget for the coming year, after slashing $19 billion in revenues that would have been raised from a hike in energy prices that was ultimately rejected, said a news report.

'After five days of (lengthy) debate on projected revenue and expenditure for the next year, the $279 billion was passed,' the Fars news agency reported, adding that the budget must now be approved by the Guardians Council.

On Sunday, MPs had approved a $298 billion budget outline for the year beginning on March 21.

However, the following day they scrapped a proposal that would have allowed the government to raise energy prices after protests that this would stoke inflation, the report added.

The budget, down from the current year's $307 billion, comes at a time when Iran is battling high inflation of around 26 per cent and reduced revenue because of the plunge in world oil prices.

Oil accounts for 80 per cent of Iran's foreign currency receipts, making the economy highly vulnerable to shifts in global crude prices. These are now under $50 a barrel, having plunged from a high last summer of $147.