By Yolande Knell
BBC News, Cairo
The film unites two of Egypt's biggest stars, Adel Imam and Omar Sharif
A new comedy which opened in cinemas in Egypt this month has achieved what intellectuals and human rights activists have failed to do.
It has got Egyptians talking about tensions between the country's majority Muslim population and its Christian minority.
The film, Hassan and Morqos, co-stars Egyptian comedy legend Adel Imam as Boulos, a Coptic Christian priest, and Alexandria-born Hollywood star Omar Sharif as Sheikh Mahmoud, a Muslim preacher.
Both play moderates forced to go into hiding and change their religious identities (becoming Hassan and Morqos, respectively) when they are threatened by extremists in their own communities.
Brought together by their parallel predicaments, the two men come to live in the same building with their families.
They become friends - even opening a joint business - and before long their children fall in love, unhindered by religious restraints.
"I think a film should have a message and one of my messages is to make people love each other," says writer Yousef Maati.
"Every day we hear that Christians and Muslims are in an eternal quarrel but when audiences see this film I think it will change something inside them."
Since the 1970s and 1980s - when there was a rise in extremist Islamist thought and Christian radicalism - there have been frequent sectarian clashes in Egypt.
Hardliners have criticised Imam, who is Muslim, for preaching Christianity
Now tensions are escalating again according to a new report by a group monitoring religious freedom.
The Egyptian Initiative for Personal Rights (EIPR) investigated two outbreaks of violence in the Fayoum area, south of Cairo, last month.
In one case there were rumours that a woman who had converted from Christianity to Islam had been abducted by her Coptic family.
It led to hundreds of Muslim villagers going on the rampage, looting Coptic shops and setting property alight. Stones were thrown at the local church.
In the second incident, Coptic residents of a small town were attacked following claims that a married Muslim woman and a Christian man were having an affair.
"Sectarian tensions and violence have reached an alarming level," says EIPR director, Hossam Bahgat.
"Often a minor fight between Muslim and Christian neighbours develops very quickly into sectarian clashes."
While Egyptian commentators are divided over the contribution that Hassan and Morqos makes to the debate about religious discrimination, Mr Bahgat welcomes it.
"Many people have written that it's a bit superficial but I believe the fact that it was made is really a positive development."
"It's a mainstream film in which the sole subject is Muslim-Christian relations - but it doesn't paint a rosy picture."
An early scene in the film introduces the reasons for hostility and anger on both sides of the religious divide.
Egyptian religious leaders profess unity but there are underlying tensions
It shows clerics on the way to an annual national convention for Muslim-Christian dialogue in Cairo.
Priests dismiss the event and complain that the government puts severe restrictions on building churches and the number of Copts in ministerial positions.
Meanwhile, Muslim scholars discuss how Copts - who make up an estimated 10% of Egyptians - control the national economy.
Such remarks are widely uttered but putting them on the big screen has broken a social taboo.
Campaigners against sectarian violence are calling for religious leaders and Egypt's government to acknowledge the problem and take steps to reduce it, making sure sectarian strife does not spiral out of control like in Iraq and Lebanon.
But angry comments on the message boards for Hassan and Morqos and calls for a boycott make it clear there is a lot to do to change prejudices.
Adel Imam, a Muslim, has been accused of preaching Christianity in his portrayal of Boulos.
Yet many thousands have been to see it and Adel Imam himself hopes it will foster national unity.
"I have made a work of art. That is what I can do. I have declared war using art against the extremists - against those who foment differences between us."
"I hope Christians and Muslims will leave the cinema and embrace and kiss one another."