* Protests at prayer point to deep enmity
* Media campaign heightens suspicions of Brotherhood
* Islamists also accused of violent rhetoric
By Tom Perry and Emad Omar
CAIRO, Aug 8 (Reuters) - When a Muslim cleric asked worshippers at a Cairo mosque to pray for people killed while protesting in support of Egypt's deposed president, one of them stopped him in his tracks.
"Why should we do that?" he asked.
Getting to his feet to make his case, the man in his fifties said anyone wishing to pray for the 80 supporters of former President Mohamed Mursi shot on July 27 should do so at the Muslim Brotherhood protest camp on the other side of town.
"This is prayer, not politics," the imam answered.
But his words fell mostly on deaf ears. Many worshippers were heading out of the door. The prayer was not read.
It was the first time in living memory anyone had objected to prayers for the dead at the mosque. But across Cairo, similar scenes have unfolded at other places of worship - a startling measure of the growing enmity many Egyptians feel towards Mursi, the Muslim Brotherhood and their supporters.
"This is impossible. I can't believe we arrived at this. May God save us," said one elderly man, observing the scene.
Since the army removed Mursi from power on July 3 in response to mass protests against his rule, political divisions have shown up in the street, the mosque, on Facebook and even in divorce courts.
In one case, a couple with three children married for 10 years split up over politics, according to a friend of the pair.
Mursi's fall and the violence and protests it unleashed are stirring deepening anger. The enmity has impaired efforts to mediate an end to the crisis. Some fear it could scar the country for years to come.
At each extreme, the crisis is painted as a struggle of good versus evil. The Brotherhood says God is on its side. So too do some in the other camp.
Hamdeen Sabahi, a leading secular leftist, has credited divine will for bringing out the masses to help topple Mursi.
The Brotherhood says it was stripped of legitimate power by treacherous generals it holds responsible for two mass killings of Mursi loyalists. It has urged followers to embrace martyrdom and its clerics have implored God's vengeance on their enemies.
The state, meanwhile, accuses the Islamists of resorting to violence, terrorism and torture. Drawing on footage of children marching in death shrouds, it has accused the Brotherhood of using minors as human shields at their protest camp - charges dismissed as propaganda by the Brotherhood.
Bolstered by a mighty state information machine and isolated reports of violence by Mursi backers, that narrative is taking hold among many who were already deeply suspicious of his group.
Millions rallied in Cairo on July 26, answering a call by army chief General Abdel Fattah al-Sisi for a mandate to crack down on "violence and terrorism" - code for the Brotherhood.
Egyptian media - both state and privately run - have taken the campaign against the Islamists to a new level.
The front page of one of Egypt's biggest state-run dailies alleged this week that the Islamists were hoarding chemical weapons at their main Cairo sit-in, one of a flurry of stories suggesting they are planning a major campaign of bloodshed.
"It's a big myth - part of the psychological war," said Khalil al-Anani of Durham University, an expert on the Brotherhood who was critical of Mursi in office but says the state is now demonising his group to justify repression.
Some diplomats have called the media war Orwellian in its twisting of language and skewing of reality. For example, state media virulently denounced visiting U.S. Senator John McCain for describing the military overthrow of Mursi as a coup.
There is a rich vein of ill will to tap, stemming from a year of Brotherhood rule in which Mursi failed to fix economic problems or build political consensus to counter perceptions that his group sought to monopolise power.
"People don't trust them, and they feel that their agenda is not Egyptian," said Mohamed Abolghar, head of the Egyptian Social Democratic Party. He fears "terrorism inside Egypt, not necessarily created by the Muslim Brotherhood, but encouraged by the Muslim Brotherhood, by their splinter movements."
Holed up at its protest camp in northeast Cairo, the Brotherhood is struggling to present its version of events to Egyptians, even as it takes foreign media on tours of the site.
"The Egyptian nation realises that this media is lying, the one that uses the violence is the one that kills them in cold blood," said Brotherhood politician Farid Ismail.
Having failed to make its case to many Egyptians when Mursi was in power, the Brotherhood now has fewer tools to make its voice heard: its TV station was switched off on July 3 and state television stopped broadcasting from the protest sit-ins.
Since then, a new Islamist satellite channel with many of the former station's presenters has managed to get on air.
Programming includes interviews with relatives of people killed or arrested since Mursi was toppled, live broadcasts from the protest sit-in, news bulletins about pro-Mursi marches, and reruns of his last speech.
"They say many things about us. They say we have diseases, that we are extremists, terrorists, that we have weapons which is totally untrue," said Maissa Abdel Latif, 50, a housewife and former accountant who returned from Paris to join the protest.
"Our channels have been closed by force, the people working for them are detained, we have no voice, our point of view is silenced," she said.
The Brotherhood's critics say the group appears to in denial. Its statements of a nation united behind Mursi's cause appear out of touch with reality.
"They are talking to themselves," said Mahmoud Al-Shamy, 24, a business administration student at Cairo University. "Every day they shout, they march but no one is listening to them. They need to move on."
The International Crisis Group, a think-tank, was critical of the discourse of both sides. Non-Islamist media had taken to calling attacks on Brotherhood offices "revolutionary" acts. The rhetoric from the Islamists was at times "chilling", it said in a report.
In talks with foreign mediators, Mursi's supporters listed a media truce as one requirement for a period of calm seen as a first step towards resolving the crisis.
"I feel very sad at what is going," said Wael Fouda, an accountant. "If the political rivals reached an agreement now, we will need decades to get through what has happened in society." (Additional reporting by Tom Finn; Writing by Tom Perry; Editing by Angus MacSwan and Paul Taylor)