Provincial governors in Iran have said they do not believe it will be possible to hold parliamentary elections scheduled for next month.
Reformists are protesting against the disqualifications
The governors said there were not enough candidates for a free and fair vote on 20 February.
Earlier this month, Iran's conservative Guardians Council barred more than 3,000 candidates from the elections.
The governors said a new date should be set for the vote, to give the council more time to review its decision.
"All provincial governors have announced unanimously that, under present circumstances, there will be no possibility of holding elections," interior ministry spokesman Jahanbakhsh Khanjani told the Associated Press news agency.
The 12-member Guardians Council has disqualified more than a third of the 8,200 people - including more than 80 sitting MPs - who applied to run in the elections.
So far it has reinstated about 700 of the disqualified candidates, after Iran's supreme leader, Ayatollah Ali Khamenei, ordered a review. It is still examining appeals and is due to announce its final decision on the others on Friday.
Student boycott call
In a letter to the interior ministry, the governors suggested a new date for the election would give the Guardians Council more time to decide whether to re-instate the barred candidates.
On Wednesday, Iran's main pro-democracy students' group called on people not to vote in the elections.
"There is no possibility of fair and free elections," the student movement, the Office for Fostering Unity, said in a statement.
"Considering that people's vote has no affect on the establishment, and there is no way to hold fair and free elections, there is no justification for people to
participate in this election."
The students urged reformist MPs to continue their protests against the poll blacklist.
President Mohammad Khatami, himself a reformist, says he still believes the row can be resolved but warned he would not accept even a single "unfair" disqualification.
"Even if one person has been disqualified unfairly, as president, I will defend his right," Mr Khatami told reporters after a cabinet meeting on Wednesday.
The president said ministers and vice-presidents had submitted their resignations in protest over the mass disqualifications.
But with negotiations continuing, he said he "will not accept resignations of any kind".