On the eve of a hard-fought presidential election, opposition leaders in the former Soviet republic of Georgia yesterday denounced the process as unfair, and called on international observers not to endorse the result.

Opposition groups say they will not recognise exit polls, insisting that they and the vote will be "rigged" in favour of Mikheil Saakashvili, Georgia's pro-western president, who is seeking re-election.

Pressure is mounting on more than 1,000 international observers who will play the key role in deciding the legitimacy of votes cast at some 3,400 ballot stations.

In an interview with the Financial Times, Levan Gachechiladze, leader of a nine-party opposition coalition, and the man most likely to come second to Mr Saakashvili, said: "The election process has not been democratic, and cannot be considered fair or legitimate."

Most opinion polls have shown Mr Saakashvili with a lead over all the other candidates, but do not clearly give him the 50 per cent plus one vote needed to avoid a second-round run-off. Mr Gachechiladze cast doubt on these and exit polls, saying they had been rigged in Mr Saakashvili's favour. He said businesses, television channels and billboard companies had refused to run opposition advertisements.

"It's impossible that the vote will be fair. It will likely be rigged in Mr Saakashvili's favour," Mr Gachechiladze said, and urged foreign election observers not to recognise the outcome.

A report issued by an election monitoring mission from the Organisation for Security and Co-operation in Europe described the election campaign as being conducted in a "highly polarised political environment".

The mission claimed to have received "information and first-hand accounts" backing some claims of "unequal campaign conditions". It said initial media monitoring efforts "indicate a lack of balance in the news coverage of most monitored TV stations, with Mr Saakashvili generally receiving the most coverage".

Other leading observer teams include the US-based International Republican Institute and National Democratic Institute, plus a team from the Parliamentary Assembly of the Council of Europe.

One observer predicted that the vote might not be handled in "ideal fashion but it is unlikely that observer teams would not recognise them as being legitimate overall. Some might be more critical than others".

Mr Gachechiladze agreed, saying: "Nobody wants instability in Georgia. This is the priority of many western states involved in the observer missions. But I think stability will come after free elections."

Mr Saakashvili, who predicts a comfortable victory for himself in the first round, admits that a second round would be harder, if all opposition votes were to go against him. Mr Gachechiladze supports a pro-western policy and Nato membership, but wants to change Georgia from a presidential to parliamentary system.