(Reuters) - Egypt´s Muslim Brotherhood planned a mass climax to its presidential campaign on Sunday, hoping to sway undecided voters and clinch victory in this week´s election when Egyptians will choose their leader freely for the first time.

On the last day of official campaigning, the Brotherhood told Egyptians to "book your place anywhere in Egypt" for evening rallies in support of its candidate Mohamed Mursi.

Brotherhood supporters seem unfazed by surveys that show their unfancied contender trailing rivals who entered the race earlier and are spending heavily in the dash for votes.

In one poll published last week in al-Masry al-Youm newspaper, Mursi was last of the four front-runners but 37 percent of the people surveyed were yet to make up their minds.

The polls, a relative novelty in Egypt, are admittedly unreliable and the large cohort of undecided voters further complicates any effort to pick a winner in the country´s first genuinely contested presidential election.

"Egyptians are a religious people and Mursi appears to be a man of God," said Farag Ibrahim, a 44-year-old in the Nile Delta town of Mansoura. "That is why I will vote for him, and because I think many others will too, and he will win."

With a grassroots network stretching into Egypt´s smallest villages, the Muslim Brotherhood has consolidated its influence since Hosni Mubarak´s overthrow in last year´s popular uprising.

Victory for Mursi would give it both executive and legislative power and consolidate a dramatic resurgence after decades of suppression by a succession of military strongmen. It would also confirm a trend of growing Islamist power at the ballot box since a wave of Arab uprisings began last year.

But the Brotherhood goes into the first-round vote on Wednesday and Thursday on the back foot.

Its first-choice candidate was disqualified by the electoral commission and rivals dismiss the second-string Mursi as a dull functionary who lacks the spark of leadership.

The Brotherhood now dominates parliament, but has achieved little influence over an army-backed government still struggling with the turmoil sparked by Mubarak´s overthrow.

In Nile Delta towns hit by an economic crisis since Mubarak´s fall, some residents say the Brotherhood deserves their votes because its social work has helped citizens through hardship.

"God willing, I will vote for them and most people in the town will do so as well. No one served us better than the Brotherhood," said Ahmed Youssef, a 41-year-old employee in a state telephone office in the large Delta town of Tanta.

"My dear friend here will do the same, won´t you?" he said, turning to a 40-year-old street trader, Mohamed Sherif al-Din.

"Mursi is a Brotherhood man and this group is the one that hires our kids and brings us goods that we don´t find in the market. God bless them and him," said Sherif al-Din, who was cycling around Tanta distributing Mursi flyers and posters.

"RELIGION IS IN THE BLOOD"

Widespread illiteracy and deep skepticism bred by three decades of managed politics under Mubarak make it hard to win over voters by setting out manifestos of policy promises.

In the first post-Mubarak parliamentary vote, spread over November to January, Islamists won more than two thirds of seats, with the Brotherhood taking the biggest share.

Liberal parties that lost out blamed their failure partly on a lack of reach compared to the Islamists, who used mosques and religious charity networks to canvas the electorate.

Brotherhood activists say criticism over the failure of the Islamist- dominated parliament to exert any sway over the government in recent months has little impact on most voters.

"Religion is in the blood of people and not everyone is exposed to media so its voice isn´t heard," said Ismail Farouk, a Mursi campaigner in the southern town of Sohag.

In Sohag and elsewhere, the Brotherhood is touting local initiatives as part of its national "renaissance project" to win voters angry at years of neglect by the government in Cairo.

Its campaigners play up Mursi´s appeal as the Brotherhood´s anointed choice to lead Egypt, in contrast to another Islamist, Abdel Moneim Abol Fotouh, who was ejected from the Brotherhood last year and is seen as a front-runner for the presidency.

Abol Fotouh is pitching to voters across the spectrum from ultraconservative Salafis to moderate Islamists and liberals. The Brotherhood is selling Mursi as the authentic religious conservative.

In Cairo, advertisements for Mursi show him in a short beard accompanied by the slogan: "Renaissance comes through the will of the people", with no mention of Islam.

Mursi banners in the industrial and agricultural Delta region north of Cairo show his beard whiter and much longer to suggest great piety. The dominant slogan changes to "Egypt´s renaissance with an Islamic foundation".

A Brotherhood strategist in Cairo, Mostafa Abdel Ghafar, played down the criticism of Mursi´s leadership talents.

"I think all people noticed that our campaign is not for Mursi as a person, but for the group´s renaissance project, which Egyptians have heard about for a year," he said.

To prove its electoral clout, the Brotherhood organized what it said was a 760 km (470 mile) human chain of supporters across Egypt on Thursday. Sunday´s planned rallies, including one outside a presidential palace in the heart of downtown Cairo, were intended as a spectacular climax to its campaign.

But the headwinds for the Brotherhood seem stronger than before the parliamentary election, when its long struggle against a monolithic Mubarak establishment finally paid off.

The Brotherhood´s rivals complained that its Freedom and Justice Party broke the electoral rules by cajoling voters at polling stations. The Brotherhood said it did nothing wrong and that many other groups campaigned on polling day.

In theory, election-day hustling could be harder this time around. The state election committee said on Saturday it would arrest anyone caught campaigning outside polling stations or even wearing T-shirts bearing campaign slogans.

A survey of campaign posters across the Delta showed more of a balance between the rival candidates than in the parliamentary vote, when the Brotherhood´s banners were clearly dominant.

"There is no way I would vote for the Muslim Brotherhood in the presidential vote as so far they have brought us nothing but chaos," said Ahmed Rafaie, a 32-year-old employee in Tanta.

"They might have got many votes in the parliament but this won´t happen again." (© Thomson Reuters 2012. 05/20/12)