By Sadeq Saba
BBC regional analyst
Reformist MPs in Iran have stepped up pressure against the conservative establishment by approving an emergency bill to amend the country's controversial electoral law.
Under the changes, candidates who have been approved in past elections will be allowed to run for office unless they are convicted of a criminal offence.
The power struggle between the two sides has intensified
It will also be harder for the conservative vetting body, the Guardians Council, to reject candidates for lack of loyalty to the country's supreme leader.
Iran's reformist MPs know there is little chance that such a fundamental change to Iran's electoral law will be approved by their hardline rivals.
The Guardians Council will see the move as a backdoor way of eroding its authority.
But, as the power struggle intensifies between the two camps, the embattled reformists are trying to put the hardliners in an awkward position.
They are also desperate to prove to Iran's disillusioned electorate that, at last, they are confronting the conservative establishment head on.
It appears that the main purpose of adopting such tactics is to galvanise public support.
The reformist MPs hope that if the Guardians Council rejects the emergency bill it will incense the voters.
But, so far, most Iranians have taken little interest in the dispute.
To the reformist MPs' disappointment, even the two week sit-in protest at parliament has not mobilised the people.
There is a profound mood of political cynicism and apathy among the public.
Reformists have never controlled the levers of power in the Islamic republic, but now their only chance of political survival is to win back public support.
Reformists are also increasing pressure on the Iranian supreme leader, Ayatollah Ali Khamenei, to break his silence and to take their side in the dispute.
In his last intervention, Mr Khamenei tried to portray himself as a neutral leader standing above political factions.
It seems the ayatollah is in a difficult position himself
He promised to intervene if the situation reached what he termed a sensitive point.
It was also reported that he had asked the Guardians Council to be more lenient towards the disqualified candidates.
But, as the supreme leader directly or indirectly appoints the members of the Council, the reformists say he should order it to reverse its decisions if he does not approve of its intransigent policies.
After approving the urgent bill in parliament, the speaker Mehdi Karrubi said that, if the Guardians Council had followed the leader's advice, there would have been no need for such legislation.
Finding a compromise?
It appears that Ayatollah Khamenei is in a difficult position himself.
Conservative institutions like the Guardians Council are the backbone of his power.
He is not willing to weaken his own authority by distancing himself from such bodies.
But he also knows that the country is now going through one of its deepest political crises in years and the whole Islamic system is in danger.
It will be interesting to see whether he can find a compromise solution to satisfy both factions.