An ultra-conservative Islamist party plans to push for a stricter religious code in Egypt after claiming surprisingly strong gains in the first round of parliamentary elections, a spokesman said.
Final results are to be announced later today, but preliminary counts have been leaked by judges and individual political groups.
Spokesman Yousseri Hamad said the Salafi Nour party expects to get 30% of the vote.
That would put it in a strong position to influence policy, although it is unclear how much power the new parliament will have with the military that took over from ousted Hosni Mubarak still in power.
Salafis advocate a strict interpretation of Islam that includes a staunch segregation of the sexes and constraints on individual freedoms.
The Muslim Brotherhood also polled strongly, indicating a trend that could give the religious parties a popular mandate in the struggle to win control from the ruling military and ultimately reshape a key US ally.
Salafi Nour appears to lead the polls in the Nile Delta province of Kafr el-Sheik, in the rural area of Fayoum, which is known for high rates of illiteracy and poverty, and in parts of their long-time stronghold of Alexandria.
Mr Hamad said the party faced its toughest challenge in Cairo because of the small presence of Salafi supporters there.
He added that his party is willing to co-operate with secular, liberal and Islamist forces, "if it will serve the interest of the nation".
This week's vote, held in nine provinces, will determine about 30% of the 498 seats in the People's Assembly, parliament's lower house. Two more rounds, ending in January, will cover Egypt's other 18 provinces.
The new parliament, in theory, is tasked to select a 100-member panel to draft Egypt's new constitution.
The Nour Party is the main political arm of the hardline Salafi movement, which unlike the more moderate Muslim Brotherhood is a new player on Egypt's political scene.
Inspired by the Saudi-style Wahhabi school of thought, Salafists have long shunned the concept of democracy, saying it allows man's law to override God's. But they formed parties and entered politics after Hosni Mubarak's removal to position themselves to make sure Sharia law is an integral part of Egypt's new constitution.
Salafi groups speak confidently about their ambition to turn Egypt into a state where personal freedoms, including freedom of speech, women's dress and art are constrained by Islamic sharia codes.
"In the land of Islam, I can't let people decide what is permissible or what is prohibited. It's God who gives the answers as to what is right and what is wrong," Mr Hamad said.
"If God tells me you can drink whatever you want except for alcohol, you don't leave the million things permitted and ask about the prohibited."
The showing in Egypt - long considered a lynchpin of regional stability - would be the clearest signal yet that parties and candidates connected to political Islam will emerge as the main beneficiaries of this year's Arab Spring uprisings.
Tunisia and Morocco have both elected Islamist majorities to parliament, and while Libya has yet to announce dates for its first elections, Islamist groups have emerged as a strong force there since rebels overthrew Muammar Gaddafi in August. They also play a strong opposition role in Yemen.
The strong showing of the Islamic hardliners worries many liberals and Coptic Christians, who make up about 10% of Egypt's population.
"We want democracy and what they want is anything but democratic," said Amir Fouad, a Coptic Christian who trained as an engineer but drives a taxi because he can't find another job.
"They want Egypt to be like Saudi Arabia, all Islamic. I feel like it will be very hard for me to live in Egypt if they rule. They will take Egypt backward."
Even some religious Egyptians see the Salafists as too extreme.
"I am religious and don't want laws that go against my beliefs, but there shouldn't be religious law," said Ahmed Abdel-Rahman, a geography teacher. "I don't want anyone imposing his religious views on me."
Meanwhile, more than 5,000 protesters demonstrated in Cairo's Tahrir Square to call for a speedier transition to civilian rule and trials for security officers accused of killing protesters.
Large crowds marched into the square carrying dozens of coffins wrapped in Egyptian flags to represent those killed in clashes with police near the square in the week before the elections.
Islamist groups did not join the protests, hanging their hopes - for now at least - on the election results.
While the number of protesters was smaller than in recent weeks, many said they had voted but still considered protest necessary.
"People haven't given up on the square just because there were elections," said Ibrhaim Hussein, who voted this week for the Muslim Brotherhood's Freedom and Justice Party. "They all have the same demands and they haven't been met yet."