Half of all religious people in Britain support the legalisation of same-sex marriage, according to a new YouGov poll.

The poll of over 4,400 adults was commissioned for a Westminster Faith Debate on same-sex marriage this Thursday.

It found that 40% of those who identified themselves as Anglicans are in favour and 47% against, while 42% of self-identifying Catholics are in favour and 48% against.

Overall, all those who identified with a religion were evenly split on allowing same-sex couples to marry, with 43% for and 43% against.

Among those who said they were currently engaging in a religious activity, 41% were in favour of allowing same-sex marriage and 46% against. Amongst the non-practising, 54% said they were in favour and 31% expressed opposition.

Amongst Anglicans, 47% of active churchgoers are against allowing same-sex marriage and 40% are in favour. Amongst non-churchgoers opinion is more equally balanced, with 44% in favour of allowing same-sex marriage and 43% against.

When asked whether same-sex marriage is right, devoutly religious people were more opposed, with the survey revealing that the more a person believed in the existence of God the less likely they were to support same-sex marriage.

Among those who said they did not know if there was a God (17% of the population), only a quarter said same-sex couples should not be allowed to marry. This rose to 38% among those who said there probably is a God (23% of the population) and 48% among those who believe there definitely is a God (26% of the population).

Similarly, those who said they rely most on religion to guide them in life and decision-making were more likely to say same-sex couples should not marry.

Among those who said they relied most on their own reason (41% of the population) for guidance, only a third (32%) were opposed to same-sex couples marrying. This compared to 56% of those who rely on religious teachings (2% of the population).

Muslims and Baptists were the most opposed to allowing same-sex marriage, while Jews, Hindus and those of no religion were least opposed.

Age and gender also make a difference. While 53% of the over-60s are against allowing same-sex marriage, this figure falls to 17% among 18 to 24-year-olds.

Men are more likely to oppose same-sex marriage (40%) than women (27%).

When asked why they support same-sex marriage, Christians in favour were most likely to cite equality (77%) and faithful love (70%). Christians who opposed expressed the belief that marriage should be between a man and a woman (79%) and that legalising gay marriage undermines the traditional family structure of a mother and father (63%).

When asked if churches are welcoming to gay, lesbian and bisexual people only 21% of the public think they are, a proportion which falls to 17% amongst 18-24 olds.

The Reverend Steve Chalke, who recently voiced support for faithful same-sex relationships, will be taking part in the debate on Thursday.

He said: "The noise of the arguments around gay marriage are clouding the real question for the Church: The nature of inclusion."