* Diallo says complaints cannot be fixed ahead of vote
* Weeks needed to address complaint over voter list, polling stations
* Deadly demonstrations have plagued run-up to vote
By David Lewis and Saliou Samb
CONAKRY, Sept 19 (Reuters) - Guinea's main opposition leader on Thursday threatened to call supporters onto the streets if authorities push ahead with a parliamentary election due on Tuesday without fully addressing complaints over preparations.
Cellou Dalein Diallo, leader of the largest opposition party and arch rival of President Alpha Conde, said it would be impossible to fix problems linked to voter lists and polling stations on time so a delay of a few weeks was needed.
The poll, meant to cap Guinea's transition back to civilian rule, has been repeatedly delayed since Conde was elected three years ago, sowing doubts amongst Guineans, investors and donors over political progress in the world's top bauxite exporter.
Dozens of people were killed in protests during months of wrangling over the election earlier this year.
A U.N.-brokered deal in July looked to have broken the deadlock but Diallo said the election commission had not fixed problems with the election list and the positioning of polling stations that both risked undermining the opposition vote.
"We know it is impossible for the corrections to be made before the 24th. We will demand they are done before we hold an election," Diallo told Reuters in the garden of his seaside villa.
"We will prevent them from forcing (the election) through. This country belongs to us all," he added. "We will restart demonstrations on Monday if necessary to demand that ... citizens' rights to take part in the election are respected."
Diallo heads the UFDG party that draws a significant amount of its support from Guinea's Peul community, who represent some 40 percent of the country's population.
Conde hails from the rival Malinke group and, in a young democracy where politics tap strongly into regional and ethnic issues, protests frequently degenerate into street clashes between mobs from both communities.
Diallo's comments come ahead of a decisive meeting on Friday between Guinea's political parties and diplomats keen to see the election, already two years overdue, finally take place.
The West African nation's economic growth forecast has been slashed to 2.9 percent for this year, down from 4.5 percent, due to the protests and political paralysis.
The unrest and a review of contracts led to major mining firms looking to tap into Guinea's iron ore reserves, seen as some of the world's largest, stalling planned projects.
Said Djinnit, the top U.N. official for West Africa and official mediator in Guinea's crisis, said earlier this week that the election commission had pledged to address opposition complaints.
But Diallo said it would not be possible to reinstate people whose names had been left off the register, remove those who appeared twice or redraw the voting map. He complained that under the current set-up, some voters in pro-opposition areas would have to walk 30 km to vote.
"People are frustrated at being left out of the process. They are convinced that it is deliberate and pre-meditated. They are ready to march to demand the respect of their rights."
Diallo rejected boycotting the poll and said that the problems could be addressed in a matter of weeks. (Writing by David Lewis; editing by David Evans)