(from BBC News)
There's a widespread belief that the penalty for leaving Islam is death - hence, perhaps, the killing of a British teacher last week. But Shiraz Maher believes attitudes may be softening.
Ziya Meral's parents disowned him when he converted from Islam to Christianity.
"They said 'go away, you're not our son.' They told people I died in an accident rather than having the shame of their son leaving Islam."
FIND OUT MORE...
Shiraz Maher (right) presents Could I Stop Being a Muslim? on Radio 4 on 22 April at 2000 BST, repeated 27 April at 1700 BST.
Or listen to it on the BBC iPlayer
Born and raised in Turkey, he decided to convert to Christianity after moving to university. He knew telling his parents would be a difficult moment even though they're not particularly observant Muslims, and he planned to break the news to them gently.
In the end, events overtook him. Before heading back to Turkey for the holidays, Ziya briefly visited a Christian summer camp where he was filmed eating a bowl of spaghetti.
The first his parents heard of his conversion was when they saw Ziya on the national news being described as "an evil missionary" intent on "brainwashing" Turkish children.
His parents decided they would rather tell people that he was dead than acknowledge he was a Christian. And Ziya, who now lives in the UK, is not alone in this experience.
Sophia, which is not her real name, faced similar pressures when she decided to become a Christian.
Coming from a Pakistani background but living in east London, 28-year-old Sophia spoke about the extreme cultural pressures her family put her under.
SENTENCED TO DEATH
Hashem Aghajari, a history professor in Tehran (pictured), was sentenced to death for apostasy in Nov 2002
He had said Muslims should not follow clerics "like monkeys"
The sentence sparked off a month of student protests and was quashed by Iran's Supreme Court
Abdul Rahman began a new life in Italy after his trial for apostasy in Kabul collapsed
"They kept saying: 'The punishment is death, do you know the punishment is death?'"
In the end, Sophia ran away from home. Her mother tracked her down and turned up at her baptism.
"I got up to get baptised, that's when my mother got up, ran to the front and tried to pull me out of the water.
"My brother was really angry. He reacted and phoned me on my mobile and just said: 'I'm coming down to burn that church.'"
For Sophia and Ziya, a lot of the prejudice they faced seemed to be borne out of cultural ideas, which are particularly ingrained in the South Asian community relating to notions of family honour.
Aghajari's death sentence sparked protests and a review
But it's too easy to say this is just a cultural problem. Dig a little deeper and you find that there is a theological argument which advocates the death penalty for apostates, which has serious implications for British society.
Last week, British teacher Daud Hassan Ali, 64, was shot dead in Somalia. His widow, Margaret Ali, said her husband was targeted by Islamists who "believe it is ok to kill any man who was born into Islam and left the faith".
Those renouncing their faith for atheism or agnosticism are viewed in a similar way to those who adopt another faith.
A poll conducted by the Policy Exchange last year suggested that over a third of young British Muslims believe that the death penalty should apply for apostasy.
Until recently, I would have shared that view, but since personally rejecting extremism myself, I've been re-examining the issues which I once regarded as conclusive.
I was staggered to learn that the Quran does not say anything about punishing apostates and that its proponents use two hadiths instead to support their view. Hadiths are the recorded traditions and sayings of the Prophet which, in addition to the Quran, provide an additional source of Islamic law.
The hadiths which relate to apostasy are linguistically ambiguous and open to interpretation. Distinguished scholars told me that the hadiths actually speak about a death penalty for treason, not apostasy. And even then, they stressed the punishment is discretionary.
I believe the classical law of apostasy in Islam is wrong and based on a misunderstanding
Scientist and imam
Dr Hisham Hellyer is a Fellow of the Oxford Centre for Islamic Studies at University of Oxford, and has researched classical Islamic law.
He believes the death penalty punishment is no longer applicable and should be suspended under certain circumstances.
Usama Hassan, a Cambridge-educated scientist and an imam, goes further and says the classical scholars were wrong in how they interpreted the Quran. He is unequivocal in denouncing those who advocate the death penalty.
"I believe the classical law of apostasy in Islam is wrong and based on a misunderstanding of the original sources, because the Quran and Hadith don't actually talk about a death penalty for apostasy."
Last year Egypt's Grand Mufti, Ali Gomaa, unequivocally told the Washington Post that the death penalty for apostasy simply no longer applies. It provoked a flurry of debate in Egypt and the wider Middle East.
The idea of killing apostates has become a resurgent theme in recent years, a fact closely-related to the increasing politicisation of Islam since 9/11.
It epitomises the "us and them" mentality felt by many Muslims between themselves and the West. And there's an uncomfortable conclusion to all this.
Muslim attitudes towards apostasy are a metaphor for the wider struggle taking place within Islam
If there is a death penalty for treason, then who defines what treason is?
Earlier this year a group of men from Birmingham pleaded guilty to charges of conspiring to kidnap and behead a British Muslim solider because they regarded him as a traitor. Joining the British army was to them treason against Islam.
So while the debate surrounding one aspect of apostasy continues, it is simultaneously throwing up an entirely new series of challenges around other issues including what should be considered treason against Islam.
When Ziya talked about what happened to him, he was just finishing a report on the experiences of apostates, called No Place to Call Home. He had interviewed 28 apostates in six different countries as part of a year-long research project.
His report found that although the death penalty is rarely applied through the courts, apostates still face gross and wide-ranging human rights abuses at the hands of the state, radical groups and local communities."
It seems that Muslim attitudes towards apostasy are a metaphor for the wider struggle taking place within Islam, between those who argue for a progressive form of Islam and those who argue for more dogmatic interpretations.
Attitudes to apostasy may be a useful barometer for judging where it's headed.