Candidates began registering on Saturday for the March 2 vote, which will be the first litmus test of the leadership's public standing since a disputed 2009 presidential vote that precipitated months of unrest.

Mehdi Karoubi was detained along with his wife, Fatemeh, when he urged supporters to gather for a Tehran rally in support of uprisings in the Arab world. His wife was later allowed out for medical treatment but he remains under house arrest.

"Officials do not believe in the people's vote and they are preparing themselves for a rubber-stamp election," his wife quoted him as saying during their weekly meeting, according to Sahamnews.

Candidate registration will last one week and then entrants will be screened for their political and Islamic qualifications by the hard-line Guardian Council electoral watchdog.

The Council has stopped hundreds of reformist candidates in the past from participating in elections. A grandson of late revolutionary leader Ayatollah Ruhollah Khomeini was banned from running for a 2008 parliamentary vote by the Council.

"The authorities want to repeat what they did in the 2009 presidential election by disqualifying the candidates ... and filling up the ballot boxes with counterfeit votes and creating an atmosphere of fear in the country," Karoubi's wife quoted him as saying, as reported by his website.

The 2009 election was followed by eight months of opposition protests that, while ultimately suppressed, pitched Iran into its deepest internal crisis since the 1979 evolution and exposed divisions within the ruling elite.

The 73-year-old Karoubi and former prime minister Mirhossein Mousavi, who is also under house arrest with his wife, competed against President Mahmoud Ahmadinejad in the 2009 vote.

They became figureheads of the postelection protests by many who believed the vote was rigged to bring back Ahmadinejad. Iranian authorities deny the charge and have portrayed the protests as a foreign-backed bid to undermine Iran's government system.