FACTBOX: Iranians vote in parliamentary election

(Reuters) - Iranians voted on Friday in a parliamentary election that conservatives are expected to win after many pro-reform politicians who oppose hardline President Mahmoud Ahmadinejad were barred from the race.

But Ahmadinejad is not guaranteed an easy ride even with a win by conservatives because the camp includes allies of the president, critics of his economic policies, and those looking beyond this election to the presidential race next year.

Following are some facts about Iran's eighth parliamentary election since the 1979 Islamic revolution:

* QUALIFICATION OF CANDIDATES:

-- Candidates for the 290-seat assembly were screened by government-run committees and the Guardian Council, a conservative body of clerics and jurists that checks hopefuls for commitment to Islam and other criteria.

-- After the vetting process, some 4,500 candidates have been left to run from about 7,600 who originally signed up.

-- Reformists see disqualifications as an attempt by hardliners to keep them out of power. The Council denies bias.

* CAMPAIGNING

-- Iran has no tradition of disciplined party membership or detailed party platforms. Three main groups -- two conservative and one pro-reform -- have emerged. But some candidates are backed by more than one group and allegiances often shift.