Campaigning began in Iran on Thursday for parliamentary elections to take place on March 2, with officials and state media calling for a big turnout to counter "enemies' threats" against the regime.
It will be the Islamic republic's first national poll since the controversial 2009 re-election of President Mahmoud Ahmadinejad.
A total of 3,444 vetted candidates are vying for the 290 seats in the parliament, known as the Majlis, to be decided by an electorate of 48 million voters.
Iran's police chief, Ismail Ahmadi Moghaddam, told the Fars news agency that his force and an additional 8,500 Basij militiamen would be on hand to ensure security on polling day.
"Police forces will firmly confront those who seek to create riots and chaos during the election," he said.
Conservatives, who dominate the outgoing legislature, are expected to secure most of the seats despite being scattered across several lists because of the lack of any broad alliance uniting the various factions.
The main reformist blocs have been banned or have decided to boycott the elections to protest against the severe crackdown against their supporters since Ahmadinejad's re-election that has led to their principal leaders being placed under house arrest.
Authorities, concerned about the risk of many voters staying away from the polls because of the predominantly conservative field of candidates, have multiplied calls for a large turnout to show they enjoy public support.
"By participating in the legislative elections, the Iranian people who turned out in their millions (during February 11 commemorations of Iran's 1979 Islamic revolution) will land another hard blow on the enemy," the supreme leader, Ayatollah Ali Khamenei, said on Wednesday.
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Iran calls its arch-foes the United States and Israel, and sometimes all Western countries, its "enemies".
One of the main parties in the elections is the United Conservatives' Front, close to outgoing parliament speaker Ali Larijani and Tehran mayor Mohammad Baqer Qalibaf, both opposed to Ahmadinejad and calling for more "rationalism" in politics.
The group, which dominates the current parliament, has to contend with the rival conservative Front of the Islamic Revolution's Endurance, which portrays itself as the defender of the directions decided by the supreme leader.
It criticises the "weak" policies of Larijani and Qalibaf towards the opposition and backs Ahmadinejad, while denouncing the president's chief of staff, Esfandiar Rahim Mashaie, who is hated by conservatives because of his vision of an Islam that is both open and nationalist.
Ahmadinejad's camp -- which at one time seemed to be thinking of presenting its own candidates before an uproar among the conservatives dissuaded it -- has been little seen so far.
However in recent days Iranian media have started to speak of individual candidates, most of them outside Tehran, thought to benefit from government support.
The two big issues facing Iran today -- the economic impact of Western sanctions, and the country's increasing international isolation because of its nuclear programme -- have been almost entirely absent from the pre-election platforms.
While the main reformist groups will not be running in the elections, some reformist candidates -- several from the 60 present in the outgoing parliament -- will be on the electoral lists.
Mohammad Khatami, a reformist former president, has not taken a public position on the elections.
His conservative predecessor, Akbar Hashemi Rafsanjani, though, has given implicit support to the reformist candidates by receiving their movements' delegations.