They called on President Hosni Mubarak on Sunday to persuade him to fulfil his electoral promise of democratic reform "before it's too late".
A statement signed by 44 prominent Muslim and Christian intellectuals said that "glaring fraud and unprecedented violence" could lead to the "collapse of the regime's and the state's legitimacy".
The first and second rounds of the elections have been marred by dozens of legal complaints and annulled results in several constituencies.
The statement also expressed concern that "the hopes of the Egyptian people in creating a democratic, just and clean system" were collapsing.
The signatories to the statement include Tariq al-Bishri, a former judge, Muna Makram Ibaid, a former MP, Aziz Sedki, a former prime minister, Abd al-Wahab al-Missiri, an historian, and Fahmy Howeidy, a columnist.
Violence, vote rigging
The statement was issued against the backdrop of growing violence across Egypt.
Vote fraud by officials was
reported across Egypt
In the past week, two people were killed and dozens wounded in clashes between "thugs" widely believed to be associated with ruling National Democratic Party (NDP) candidates and supporters of other candidates, mainly from the Muslim Brotherhood.
The statement also follows on the heels of alleged voting irregularities.
Judge Nuha al-Zaini, who supervised elections in Damanhur, 140km north of Cairo, published her account of electoral fraud that put Mustafa al-Fiqi, an NDP candidate, ahead in the second round of elections.
According to al-Zaini's signed testimony, Jamal Hishmat, a Muslim Brotherhood candidate, was "at least" 25,000 votes ahead of al-Fiqi's 7000. But the official results announced by the Ministry of Justice on Monday pronounced al-Fiqi, a liberal intellectual, the winner.
Al-Zaini's testimony was immediately backed by 137 judges who supervised elections in other polling stations in the same city of Damanhur.
The case was referred to the public prosecutor.
The scandal is the latest in the politically congested climate of Egypt.
"There were high hopes that the parliamentary elections were going to reflect the will of the Egyptian people. Nobody expected the flagrant [state] intervention, violence, rigging or arrests"
Salama Ahmad Salama,
Salama Ahmad Salama, a senior columnist in the daily Al-Ahram newspaper and one of the 44 who signed the statement, told Aljazeera.net: "There were high hopes that the parliamentary elections were going to reflect the will of the Egyptian people. Nobody expected the flagrant [state] intervention, violence, rigging or arrests."
The situation is so grave, Salama said, the ruling NDP has discussed the possibility of dissolving the coming parliament.
Counsellor Yahia al-Rafia, honorary president of Egypt's Judges Union and another of the signatories, told Aljazeera.net that such a step would damage Egypt's democratic reforms process.
If the coming parliament is dissolved because of its illegitimacy, "we will return to point zero in this country".
The three-stage parliamentary elections are due to end on 7 December.