100,000 people married under Islamic Sharia law in the UK do not have legally recognized marriages.
A new Channel 4 documentary entitled The Truth About Muslim Marriage shows the plight of women who suddenly discover they have no legal rights after their Sharia marriage falls apart.
A British woman named Habiba, who appears in the documentary, had four children with her husband before learning they were never legally husband and wife.
She would later learn he was legally married to another woman. When she left her husband she lost her home.
It's estimated that as many as 30-thousand British Muslim men may have more than one wife.
And many Muslim women in Britain are reportedly unaware that their religious marriages are not legal under British law, so in a divorce they do not have rights and protections in family court.
A national campaign called Register Our Marriage is trying to change the law so that all Muslim weddings would have to be registered.
But others do not want Islamic Sharia Council rulings to have the weight of law in Britain, and making Sharia marriages legal, without a corresponding civil ceremony, could set a dangerous precedent.