More than 500 politicians and intellectuals in Iran have announced that they will not take part in the presidential election next month.
All the candidates will now be vetted by the powerful Guardian Council
In a statement, they said that the 17 June poll cannot be free and fair because Iran's Guardian Council was depriving people of free choice.
The conservative Guardian Council has the powers of vetting the candidates.
A record 1,010 people have registered to run in Iran's presidential election next month, the interior ministry says.
Registration closed on Saturday and aspiring candidates will now wait while their applications are vetted.
'Chosen by state'
The statement was signed by some former members of parliament and also intellectuals who supported reformist President Mohammad Khatami.
MAIN ASPIRING CANDIDATES
Former President Akbar Hashemi Rafsanjani
Tehran Mayor Mahmood Ahmadinejad
Former police chief Mohammed Baqer Qalibaf
Former Revolutionary Guard head Mohsen Rezaei
Former TV and radio chief Ali Larijani
Mostafa Moin, Khatami ally
Former parliamentary speaker Mehdi Karroubi
Ebrahim Yazdi, dissident
Aazam Taleghani, female dissident
It said that "the people only have the freedom to choose from among those candidates chosen by the state".
"People are being called to participate while many of the most important circles of power and the appointed people have complete control on all the avenues of executive power," the statement said.
The Guardian Council has already said that 89 women - registered as candidates - will be disqualified.
It now has 10 days to complete the vetting procedure.
The Guardian Council caused outrage during last year's parliamentary election by disqualifying some 2,000 candidates and in effect disqualifying most reformers from standing.
But correspondents say the council may be more cautious this time, fearing a low turnout could damage its legitimacy.
The candidates range in age from a 16-year-old boy to an 86-year-old man, AP news agency says.
Former President Rafsanjani is the best-known candidate
Among those tipped to make it through to stand is former President Akbar Hashemi Rafsanjani.
Mr Rafsanjani, who was president twice from 1989 to 1997, is seen as a pragmatic conservative, open to better ties with the West but more socially conservative than the reformists, the BBC's Tehran correspondent Frances Harrison says.
The Mayor of Tehran, Mahmood Ahmadinejad, and the former national police chief, Mohammed Baqer Qalibaf, are also in the running.
Several political dissidents have registered, as well as the non-political former national goalkeeper Nasser Hejazi.
The number of candidates is up from the previous record of 814 in the 2001 elections.
Mr Khatami is barred by the constitution from seeking a third consecutive term.