One of the main challengers in Egypt's first contested presidential election is calling for a re-run of Wednesday's vote because of alleged irregularities.
Opposition groups have alleged widespread voting irregularities
Ayman Nour said he would make a complaint to the electoral commission, and take his case to court if required.
Accusations include voter intimidation, multiple voting and the absence of indelible ink from some poll stations.
Election officials have defended the fairness of the vote, which incumbent Hosni Mubarak is expected to win.
The BBC's Heba Saleh in Cairo says it is highly unlikely that the election will be re-staged.
The results are expected later this week.
Correspondents say turnout does not seem to have been high.
Nine candidates are challenging Mr Mubarak, who is seeking a fifth six-year term.
The government hailed the poll in the Arab world's most populous country a success, but opposition groups and rights bodies allege widespread vote fraud.
"We will call for... a re-election," Mr Nour, of the Ghad (Tomorrow) party, told Arabic TV channel al-Jazeera.
The politician said earlier that he believed only 15-20% of people voted in rural areas, and 3-5% in cities.
An aide to Mr Nour told Reuters that the planned appeal was "not about winning or losing, but about due process".
Poll monitors have cited irregularities, and say that voters in several areas were bussed to polling stations and instructed to vote for Mr Mubarak.
Government officials played down the alleged violations, and said they should not diminish a major step towards democracy.
"If there were irregularities they were very limited and in no way did they have any effect on the final result of the election," one of the managers of the Mubarak campaign told al-Jazeera.
The US said the vote was "a beginning", and "a historic departure for Egypt".
Our correspondent says this may have been a flawed election, but for many Egyptians the poll's main value is that it has established the principle of a competitive race for the top job.
If no candidate polls 50%, the two with the highest number of votes proceed to round two
Egyptians over 18 are required to vote by law. There are over 32m registered voters out of a population of some 74.9m
Presidents elected for six-year term
However, our correspondent said she did not see many people rushing out to vote.
Many Egyptians are disillusioned with politics after decades of authoritarian rule and state influence in the media, she says.
Mr Mubarak is the only leader the majority of Egyptians have known and most of his challengers are not even taken seriously as politicians.
Only two can be said to have constituencies.
One is Mr Nour, who says he would rule for two years only, in which he would lay down the foundations of a democratic state.
The other serious contender, Nomaan Gomaa, heads the Wafd, the once vigorous liberal party that fought for independence from Britain but that has been seriously weakened by the political restrictions of the past 50 years.