For years, the rugged Mediterranean shoreline here has been a favorite necking place for young Egyptian couples. But now menacing new messages have been spray-painted on the rocks.

“Would you find it all right for your sister?” one message says, addressing the men who bring girlfriends to the rocky area where waves break. “God sees you.” Other messages decry alcohol. One says simply, “Enough sins.”

The fresh scrawls are the work of Islamists who are emerging from the fringes of Egyptian society with zeal and swagger. Their graffiti and billboards calling for a more conservative Egypt have become pervasive here in recent months, part of a rapidly growing debate about what should emerge from a revolution that toppled an autocratic leader and unleashed long-subdued social and political forces.

“There is going to be a battle between two visions for Egypt,” said Abdel Moneim El-Shahat, a leader in Egypt’s fundamentalist Salafist movement, whose members spent long years in jail under President Hosni Mubarak.

With parliamentary elections scheduled for this fall, the Salafists are poised to emerge as a powerful political force in the contest, which could become an unofficial referendum on how piously the Arab world’s largest nation should be governed in the post-revolutionary era.

Salafists are loosely organized around the ideal that Islam ought to be restored to what they consider the pure, fundamental way the prophet Muhammad and his immediate descendants practiced it.

In Egypt, Salafist men shun alcohol and grow long beards. They insist that female relatives refrain from working outside the household and cover their faces with the garment known as the niqab. Unlike the Muslim Brotherhood, they have not actively participated in Egyptian politics and have not opened their political ranks to minorities, such as Coptic Christians.

Although less politically experienced than the better-known Brotherhood, Egypt’s Salafists could significantly alter the political landscape of a country that was run by a secular autocrat for three decades. Salafist leaders are forming political parties, tapping into the region’s burgeoning blogosphere and reintroducing themselves in communities where they had long been regarded as pariahs.

Abdallah al-Ashaal, a former Egyptian diplomat who is running for president as a liberal, said the Salafists will be able to rally a large base of supporters at the polls.

“They vote according to orders, not to convictions,” he said.

No one — not even budding Salafist politicians — is predicting a windfall on election day for the movement, which includes leaders who profess admiration for slain al-Qaeda leader Osama bin Laden. But Shahat and other influential Salafists say they intend to play a key role in the drafting of a new constitution to ensure it reflects a strict interpretation of Islamic law.

Salafist leaders have not spelled out a clear political platform or said how far they think the state should go in ensuring that Islamic law is the anchor of morality, justice and governance in the new Egypt.

Senior Muslim Brotherhood politicians and Salafist leaders have demurred when asked recently whether they would seek to ban alcohol or force women to be veiled. Ashaal pointed out that sharia law prohibits alcohol consumption but that it “doesn’t give us a right to inspect people’s homes.” It also dictates that women wear veils, he said, but does not allow the government to compel them by force to do so.

Eye toward Saudi Arabia

Saudi Arabia is the country that Egypt should try to most emulate in the future, said Ashaal and Mohammed Mursi, the leader of the Brotherhood’s new political party. They praised the ultraconservative brand of Islam, known as Wahhabism, that is strictly enforced in the kingdom.

Today’s leaders of Egypt’s Salafist movement came of age alongside Islamists from armed groups that carried out attacks against the government in the 1980s and 1990s, seeking to overthrow the government and establish an Islamic state. Salafist and Muslim Brotherhood leaders now claim no affiliation with armed organizations such as Islamic Jihad or al-Gamaa al-Islamiyya, and they vow that their groups have renounced violence.

Egyptian Islamists have long felt that Mubarak’s government, which was largely secular, did not reflect the nation’s religious tenor. The ousted leader kept the Muslim Brotherhood on a tight political leash, giving the group just enough breathing room to maintain the semblance of a viable opposition.

The regime was ruthless toward the Salafists, whose founding members include figures that inspired violent jihadists. Hundreds of Salafist leaders were detained in Mubarak’s Egypt for years under the country’s emergency law, which gives the state the right to imprison people indefinitely without charges. Most have been released in the aftermath of the 18-day uprising.

Shahat, a prominent Salafist scholar who was frequently detained and hassled by the former regime’s security forces, said Islamist politicians could get up to 40 percent of the seats in the new parliament. The Brotherhood, he said, probably will get most of those, but Salafists, he predicted, could secure up to 10 percent.

“Many of the leaders are now free, and they are introducing themselves to the media and society,” Shahat said. “They are introducing themselves to society in a peaceful way, reminding people we gave up violence even before the revolution.”

‘Why are people so afraid?’

Prominent among those is Mamdouh Ismail, a Cairo defense lawyer who was among the Islam­ists rounded up after the 1981 assassination of President Anwar Sadat. Ismail, who has represented numerous Islamist militants, was detained again in 2007 and questioned about alleged links to al-Qaeda. He has denied wrongdoing.

On a recent afternoon, as he held court in his spacious office in Cairo’s lawyer’s syndicate wearing a gray striped suit and a blue tie, Ismail looked far more like a budding politician than a militant. Bearded men sat on the couch on the opposite end of the office, drinking tea while waiting to speak to him. A colleague was using a camera to prepare Salafist videos; they featured declarations from women wearing niqabs.

Salafists were widely blamed for instigating a recent spate of clashes between Muslims and Christians that left more than a dozen people dead and hundreds wounded. Ismail said he is alarmed by what he called false rumors being spread through Cairo neighborhoods suggesting that Salafists have set women on fire for not covering up.

“Why are people so afraid?” he said. “Because it has become very clear since the revolution that there is a lot of interest on the street in Islamic movements and Islamic thinking, despite the best efforts by liberals.”

But as Salafists have assumed a higher profile in cities and villages around the country, some residents have become fearful. In the low-income Imbaba district of Cairo, a Muslim mob reportedly led by Salafists cried “Victory for Islam!” as they clashed with Coptic Christians and set a church on fire last month.

“The sense that your old neighbor would do this to you, that was an awful feeling,” Coptic priest Zusima al-Antouni said, speaking near St. Mina, the Coptic Orthodox church torched May 7. “The blame lies at the feet of the people who let the Salafists out of jail.”

Special correspondent Ingy Hassieb contributed to this report.