MPs approved a budget allowing imports worth up to 30 trillion rials (3.2 billion dollars) in the new year beginning on March 20.
Iran has become a net importer of diesel and petrol because of high consumer demand, partly because it spends around 100 billion dollars (68 billion euros) a year subsidising fuel prices.
Unleaded petrol in Iran currently costs around 1,000 rials (10 dollar cents) a litre.
Iran, OPEC’s number two oil producer, makes around 45 million litres (12 million gallons) of petrol a day but has previously been forced to import up to 25 million litres (6 million gallons) extra every day to meet demand.
The government introduced fuel rationing in June in a bid to dampen demand, and since December drivers have been limited to buying 120 litres (26 gallons) of petrol a month.
This has cut consumption, and the country is currently importing around 15 million litres (4 million gallons) a day.
Smugglers also illegally export diesel and petrol to neighbouring Iraq, Turkey and Pakistan, where it is sold for a profit.
MPs are also considering a dual pricing system under which non-rationed petrol could be sold alongside rationed subsidised fuel, the ISNA student news agency said.
