The assembly of the judges - some of whom had favoured a boycott - known as Egyptian Judges' Club was tipped on Friday as an important measure of the credibility of Egypt's first ever contested presidential election.
Judges' Club chairman Zakariya Abd al-Aziz read a resolution which was approved by a majority of the 2500 judges who attended the meeting.
He warned the electoral commission that if the 8000-strong syndicate's demands were not met, the poll's transparency could not be guaranteed and that the judges would distance themselves from the result.
"We will tell the world that we cannot endorse the election's result," he said.
Egypt's all-powerful electoral commission - which opposition groups charge is controlled by President Hosni Mubark's ruling party - has rejected the principle of other election monitors, Egyptian or international.
One of the main conditions listed on Friday by the judges was the presence in polling stations of monitors from civil society NGOs.
They also demanded that recently appointed state prosecutors be excluded from the judges' monitoring contingent, that a copy of the results for each polling station be handed to party delegates and that the decision to expel 2000 judges from the syndicate be annuled.
The electoral commission had announced that up to 13,000 judges would monitor the vote but Abdel Aziz said the list of names he was given included people who had died, resigned or left Egypt.
"We are here today to support the judges, hoping they will decide to protect their legitimacy by boycotting the election completely since it doesn't meet their demands for a clean monitoring process"
The syndicate decided not to hand the commission an ultimatum but Abdel Aziz launched stinging attacks against its chairman, Mamduh Marai, charging he was "violating the law".
"Judicial and Egyptian respectability as well as the country's future are in your hands," he said. "If this election takes place the same way the referendum did, the highest office ... will be under threat."
The Judges Club charged in July that the May referendum that approved a contested presidential race had been marred by widespread fraud.
"We will not endorse a rigged election another time," Abdel Aziz said.
The judges received the support of some 200 demonstrators, including several supporters of the opposition Kifaya (Enough) party, gathered in front of the syndicate to call for a boycott.
"We feel an injustice is happening," said Kifaya leader George Ishaq, as demonstrators waved banners addressed to Mubarak that read: "Don't elect him, sue him".
"We are here today to support the judges, hoping they will decide to protect their legitimacy by boycotting the election completely since it doesn't meet their demands for a clean monitoring process," said Ahmad Salah, a leader of the Youth for Change movement.
"It's clear that the restrictions imposed do not allow for a complete monitoring and leaves the door open to the same fraud that marked the previous elections," he said.
Mubarak, who has been in power since 1981, is widely expected to secure re-election during the first round but a predicted low turnout could harm his legitimacy.