TEHRAN, Iran — Iranian reformists accused conservatives on Monday of employing totalitarian tactics and said they were considering boycotting next month's legislative elections in frustration with a deepening political crisis.

The Guardian Council, a powerful, unelected body that supervises elections, on Sunday vetoed legislation that sought to curb its powers and force a reversal of the disqualifications of thousands of candidates in next month's election.

Students said they planned mass protests against the hardliners.

"Students will join professors of all universities in Tehran today to support disqualified prospective hopefuls and denounce hardliners who are restricting people's choice," reformist student leader Hossein Baqeri said Monday.

The veto is likely to provoke a boycott of the Feb. 20 parliamentary elections as reformists have warned they would not take part in polls where more than a third of the candidates had been prevented from running.

"The rejection means there is no will on the part of hardliners to resolve the political crisis through logical methods. It only pushes reformist legislators to harden their position and seriously consider mass resignations and boycotting the polls," said Mohsen Armin, a prominent reformist legislator and one of those disqualifed.

He said boycotting the elections has become a serious option for reformists, including those who had qualified to run again.

President Mohammad Khatami's administration, he added, "is expected to seriously consider not holding the elections if things don't change."

The bill parliament passed had sought to overturn the disqualification of more than a third of the 8,200 candidates -- including more than 80 reformist sitting legislators, who had registered for the elections. Reformists have condemned the disqualifications as an attempt by hardliners to skew the elections in their favour.

Leading reformists had announced the veto, and the Guardian Council issued a statement Monday confirming it, state-run Tehran radio reported.

Another reformist legislator who has been disqualified, Fatemeh Haqiqatjou, told the AP that with its veto, "the Guardian Council effectively pushes the country toward greater political chaos.

"The rejection brings reformers and all those who want free and fair elections closer to boycotting the elections," Haqiqatjou said. "Iranians never allow dictators to decide for them."

In a session broadcast live on state radio Sunday, legislators voted by standing to approve the bill. They categorized it as "triple-urgent," meaning highest priority. It was the first time since Iran's 1979 Islamic revolution that parliament has approved a triple-urgency bill.

The bill would have amended the National Elections law to force the Guardian Council to reinstate all disqualified candidates unless there is legal documentation to prove them unfit for parliament.

The council's members are chosen by Iran's supreme leader, Ayatollah Ali Khamenei, who has asked the body to reconsider its disqualifications. The council has reinstated only a few hundred candidates. Its slow response has angered reformists, who say it does not act without the supreme leader's approval.

On Friday, Khatami and parliamentary speaker Mahdi Karroubi warned that unless the disqualifications were withdrawn, there would be no liberal candidates in more than two-thirds of the electoral districts.

The battle over who can run on Feb. 20 has turned into Iran's worst political crisis in years.

Reformers believe the conservatives are trying to tilt the elections so they will regain control of the 290-seat parliament. In the 2000 polls, the hard-liners lost the majority in the assembly for the first time since the 1979 revolution.

Hardliners claim the disqualified candidates failed to meet the legal criteria.