Islamists look set to dominate the next Egyptian parliament, but mutual suspicion between the two main groups, the Muslim Brotherhood and the Nour Party, makes it unlikely they will join in an exclusive governing alliance.
The split in the Islamist camp leaves scope for liberals and secularists to play a part in the first post-election government and reduces the chances of any one group restoring the kind of de facto one-party rule that Egypt experienced from the 1950s until a popular uprising toppled Hosni Mubarak on February 11.
The Nour Party, created this year after Mubarak's fall, is the largest of Egypt's new Salafi parties, which draw support from ultra-conservative Muslims who try to emulate the example of the Prophet Muhammad and his 7th-century companions.
Its success in the first round of parliamentary elections, with 24.4 percent of the vote, has been the biggest surprise in the new political landscape. Most analysts expected the Salafis as a whole to win 10 to 15 percent of the vote.
Essam el-Erian, vice-president of the Brotherhood's Freedom and Justice Party (FJP), told Reuters on Monday it was too early to say what form a ruling coalition might take because less than one third of parliamentary seats have been decided.
In the first round the FJP was way ahead of any rivals, with 36.6 percent of the vote.
We are still in the Democratic Alliance and we are committed to our partners. We have never spoken about any other alliance, Erian added. The alliance includes two non-religious parties, the Karama Party and the Ghad Party, although the Brotherhood is very much the dominant element.
Since Mubarak was ousted, the Brotherhood has emphasised the political reform agenda it shares with a broad range of groups that took part in the uprising, playing down the socially conservative agenda usually associated with Islamist movements.
Erian told Reuters in October, before the level of popular support for the Salafis was evident, that the ultra-conservatives would be a burden on any coalition because they are newcomers to political life (while) we have many years of experience and we are widespread all over the country.
A centrist coalition is what the Brotherhood wants, depending on the final results, said political analyst Issandr el-Amrani. They have reservations about the Salafis because they could be disruptive on domestic politics, with their mediaeval interpretations of Islamic law, for example.
But if the Salafis really end up with 25 percent of the vote, they will be a powerful force on cultural issues anyway, he added.
Nour Party leader Emad Abdel Ghaffour, on the other hand, made clear he would not play second fiddle to the Brotherhood. We hate being followers, he told Reuters in an interview.
They always say we take positions according to the Brotherhood but we have our own vision... There might be a consensus but ... we will remain independent. We don't rule out that they may marginalise us and portray us as the troublemaking bloc, he added.
The experiences of other parties who have allied with them (the Brotherhood) in the past are bitter. They always speak of it with reproach, he said.
The Nour Party has indicated it wants to take part in government in partnership with others.
On Sunday two newspapers quoted party spokesman Nader Bakkar as saying Nour had proposed four ministers for a new cabinet that former Prime Minister Kamal el-Ganzouri is now trying to form. The party later denied it had made any such proposal.
And Ali Abdel Al, writing in the Nour Party newspaper, said: They (Islamists in general) believe in the need for partnership with the other political elements and parties that exist in the country, liberal and leftist, and the idea of forming a purely Islamist government might be unacceptable to their minds now more than any time in the past, for many reasons.
Analysts say a major pragmatic disincentive for Islamist leaders to go it alone in government is the knowledge that Egypt faces serious economic problems that might make it difficult for the Islamists to meet the expectations of their constituents.
The two most obvious areas are in banking and tourism. The Salafis want to phase out non-Islamic banking, the sale of alcohol and bare flesh on Egyptian beaches. But the government has interest-bearing obligations that do not mature until after 2020, and tourism, mainly for sun and sand, accounts for about 12 percent of the Egyptian economy.
We have a plan to amend the banking law, but it's difficult to put it into effect all at once, in case the economy collapses, said Ashraf Thabet, one of the Nour Party's new members of parliament, quoted in the newspaper Al-Masry Al-Youm.
Both the Brotherhood and the Salafis share some long-term objectives and both have emphasised gradualism, persuasion and consensus in their aspirations to make Egypt more Islamic.
But the Brotherhood is an overtly modern organisation led by middle-class professionals such as doctors, lawyers and engineers, with very few clerics as prominent members. The Salafists have more clerics in the leadership and appear to appeal to poorer sectors of society than the Brotherhood.
In voting in the rural province of Fayoum last week, farmers and their relatives voted for the Nour Party in large numbers, saying that they liked its Islamist programme, that they knew the candidates and trusted they were clean and honest.
I'm voting for the Nour Party because sharia (Islamic) law and religion are what matter most, said Arafa Ahmed Abdel Kader, a factory technician. And the candidates are people from the village, people that we know and trust, he added.
In Cairo on Monday, voters had mixed opinions on whether the Brotherhood and the Salafis would work together to create a dominant Islamist bloc.
Secretary Nora Tawfik, 34, said she wanted the Brotherhood to link up with the liberal non-religious Egyptian Bloc, which has about 13 percent of the vote from the first stage.
I would hope they would be pragmatic enough to ally with the Bloc to balance things out, but my gut feeling tells me that they will ally ideologically with Nour despite their differences now, she added.
But Jihan Moussa, a 39-year-old pharmacist, said she thought the Brotherhood's party would not ally with the Nour because of their ideological differences. I am against also this idea of one party or thought being dominant because if that happens then they will most definitely turn into dictators, she said.
(Additional reporting by Maha El Dahan, Tamim Elyan and Edmund Blair; Editing by Alistair Lyon)