TEHRAN (Reuters) - Iranians vote on Friday in aparliamentary election that conservatives are expected to winafter many opponents of President Mahmoud Ahmadinejad werebarred from running as candidates.

Many pro-reform politicians, the staunchest critics of thehardline president, were disqualified from the race in apre-vote screening process that has narrowed the field.

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

Parliament does not decide on major policy issues such ashow to handle Iran's nuclear row with the West. But foodprices, not foreign policy, are what most ordinary Iraniansworry about.

"I hope this time they do a better job and pay moreattention to the economy, the housing problem and inflation,"said Soraya Tavasoli, a middle-aged woman backingconservatives.

Others are wondering whether to vote at all, despite a callfrom the clerical establishment for a high turnout to defyIran's "enemies" — the United States and its Western allies.

"Hollow promises (by politicians) don't count. What countsis action," said Zahra Mehramiz, 47, who plans to stay home.

The election may offer pointers on Ahmadinejad's chancesfor re-election in 2009 although that may depend more onwhether he retains the approval of Iran's top authority,Supreme Leader Ayatollah Ali Khamenei, who has often praisedhim.

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"People in choosing parliamentarians should also consider… voting for those who can pave the way for the currentgoverment which is active and willing to serve," Khamenei wasquoted as saying by Kargozaran newspaper.

Analysts say the vote may give only a partial picture ofAhmadinejad's popularity after the unelected Guardian Council,which checks hopefuls for commitment to Islam and othercriteria, barred many reformists. The council denies bias.

"People are not given a free choice about who to vote for.Therefore it's not a fully accurate guide to political opinionin Iran," said one Western diplomat.

Reformists seeking political and social change had hoped tocapitalise on public discontent about inflation, now at 19percent. But after the vetting process, they may struggle tokeep the 40 or so seats they hold in the 290-seat assembly now.

They say the election is unfair but have still urged Iran's44 million eligible voters to turn out.

Conservatives, who pride themselves on their loyalty toIran's system of clerical rule, control the outgoing parliamentand backed Ahmadinejad when he ran for president in 2005. Manyhave since become more critical of his economic policies.

While reformists say Ahmadinejad's fiery speeches helpedprompt three rounds of U.N. sanctions, many conservatives backhim for vowing no compromise with the West, which accuses Iranof seeking nuclear weapons. Tehran denies the charge.

(Additional reporting by Alistair Lyon, Zahra Hosseinian,Fredrik Dahl; Editing by Catherine Evans)