* Abol Fotouh buoyed by Salafi backing
* Salafi snub latest blow to Brotherhood
* Official campaigning gets under way on Monday
* Parliament suspends sessions in protest (Adds suspension of parliament)
By Tom Perry
CAIRO, April 29 (Reuters) - The Muslim Brotherhood's bid to win the Egyptian presidency suffered a major blow when hardline Islamists endorsed its candidate's main rival in a race that heats up on Monday with the start of official campaigning.
The historic free election to decide who replaces fallen autocrat Hosni Mubarak is shaping up as a ballot box struggle between Islamists who were oppressed by the deposed president, politicians who at some point were part of his government and liberals and leftists seen to have little chance of winning.
The Nour Party of the Salafi movement, which espouses a puritanical version of Islam, on Saturday endorsed Abdel Moneim Abol Fotouh, a former Brotherhood member ejected from the mainstream Islamic movement last year, for the presidency.
That should bring to Abol Fotouh many of the votes that propelled the Salafis into second place behind the Brotherhood in Egypt's parliamentary elections.
Abol Fotouh, 60, has presented himself as a moderate Islamist, holding out a vision of sharia (Islamic law) that promotes the interest Egypt's diverse society at large, though critics say he has yet to clarify exactly what that means.
His support base includes some of the liberals who had supported Mohamed ElBaradei, the Egyptian former head of the U.N. nuclear watchdog who withdrew from the race in January.
The Salafi endorsement was the latest boost to Abol Fotouh's campaign after the disqualification of other top Islamist contenders, including the Brotherhood's first-choice, Khairat al-Shater. Abol Fotouh chances have also been enhanced by the broad support he has built across the political spectrum.
"This is a big blow to the Brotherhood. It could even be considered the biggest blow yet," said Shadi Hamid, an expert on Islamist groups based at the Doha Brookings Center.
"The Brotherhood has to think seriously about the perception of being defeated, and defeated by Abol Fotouh."
Abol Fotouh was ejected from the Brotherhood last year when he decided to defy its wishes by running for the presidency. He is described by Brotherhood experts as a reformist who was at odds with more conservative figures who now lead the movement.
"INCENTIVE"
Mohamed Mursi, the Brotherhood's current candidate, went on the campaign trail on Sunday in southern Egypt. "This (Salafi decision) creates an incentive for our members to make more effort," said Mahmoud Ghozlan, spokesman for the Brotherhood.
The Nour Party and al-Daawa al-Salafi, the religious movement to which it belongs, decided to back Abol Fotouh after its board heard presentations from the top Islamist candidates.
"We see him as the most appropriate person for this period," said Mohamed Nour, a spokesman for the Nour Party. "He does not belong to any party and he adheres to principles and the project of Islamic civilisation to a great extent," he said.
"We will only pick someone who is the best for leading Egypt, even if we disagree with him in some ideological matters," he added, without elaborating.
The Brotherhood, founded in 1928, had been dismissive of the Salafi parties that were set up last year. But after deciding at the end of March to throw its hat into the presidential ring, the Brotherhood sought to rally the Salafis to its side.
But as it has courted the conservative right, the Brotherhood has faced ever sharper criticism from liberal reformists and others who say it has rowed back on promises that it would not seek to dominate the post-Mubarak era.
One area of dispute has been who should draft a new constitution that could well curb presidential powers, casting doubt on how much authority the incoming head of state will have. Another unresolved question is how much power the long influential military might continue to wield behind the scenes.
Since the election, the Islamist-dominated parliament has been seeking to influence government in a way unseen in the Mubarak era. The Brotherhood has urged the ruling generals to sack the government and appoint a new one that it would lead.
In a sign of tension with the military council, parliament decided to suspend its sessions until May 6 in protest at ministers' failure to show up for parliamentary hearings and the generals' refusal to appoint a new cabinet.
"I am of the opinion that we suspend this week's sessions until we reach a solution to this crisis," said speaker Saad al-Katatni, a member of the Brotherhood. The chamber voted in favour.
Seeking to break the impasse over the constitution, the military council met political parties on Saturday and reached what state media described as an agreement on how the 100-person body that is to draft the constitution should be formed.
Participants described the deal as "a general framework", indicating there could be more discussion ahead. (Additional reporting by Ali Abdelati and Shaimaa Fayed; Editing by Mark Heinrich)
Our Standards: The Thomson Reuters Trust Principles.
