The Iranian parliament has voted to consider a proposal to pick another city as the nation's capital, potentially moving the seat of government from the overcrowded Tehran.
Iran's official news agency IRNA said on Tuesday that politicians had accepted outlines of the proposal with 110 out of 214 present lawmakers supporting it. The chamber has 290 seats.
Under the plan, a council would be set up and spend two years studying which alternate location would be best.
While there was no suggestion in the bill which cities would be looked at, several central and western cities already have said they would like to be considered.
Supporters of the plan said Tehran, with a metropolitan population of 12 million people could not support the capital.
They pointed at the heavy pollution, the city's traffic jams and risk of earthquakes there. Iran is located on several faults and experiences a light earthquake a day, on average.
Still, moving the capital seems unlikely, due to the high cost involved.
Vice-president Mohammad Ali Ansari, who is in charge of parliament affairs, said he opposed the plan, which he said was was not practical, and that politicians did not have the power to order the capital to be moved.
He said relocating the capital was part of main policies of the ruling establishment, a reference to the authority of Ayatollah Ali Khamenei, the Supreme Leader, who has final say on all state matters.
"It is impossible to decide about making the decision on moving without consulting his Excellency," Ansari said.
Parliament speaker Ali Larijani opposed the plan over the cost and said the Guardian Council, a constitutional watchdog that vets the bills, would likely reject it as well.
Saeed Leilaz, a Tehran-based political-economic analyst, also said the plan was not feasible.
"This will cost dozens of billion dollars for a government that has not enough to pay the monthly salary of its staff," Leilaz said.
Iran has been crippled by Western sanctions over its disputed nuclear power programme, which has cut its access to the oil money that makes up to 80 percent of its foreign income and 50 percent of budget.
Politicians and officials occasionally have raised the idea over the past 50 years, before the 1979 Islamic Revolution that ousted King Mohmmad Reza Pahlavi.
US advisers reportedly had asked the king to relocate the capital because it was too close to borders of the Soviet Union.
During World War I, the Iranian government decided to move the capital temporarily when Russian and British forces occupied parts of the country, although the order was never carried out.