Eighteen Church of England bishops used a letter in a Sunday newspaper to express concern that the policy will leave children facing "severe poverty and potentially homelessness."

In a letter to the Observer the bishops gave their backing to a series of amendments to the Bill which have been tabled by Bishop of Leeds and Ripon John Packer with the assistance of the Children's Society.

The amendments have also reportedly received the support of the Archbishop of Canterbury and the Archbishop of York.

The Children's Society has warned that a cap on the total benefits households can claim could make more than 80,000 children homeless and push many thousands more into poverty.

It has proposed that the Bill should be altered to remove child benefit from household income for the purposes of calculating the level of the cap.

The charity also suggested that certain vulnerable groups be exempt from the cap and the introduction of a grace period for newly unemployed families.

In their letter the bishops wrote: "The Church of England has a commitment and moral obligation to speak up for those who have no voice.

"As such, we feel compelled to speak for children who might be faced with severe poverty and potentially homelessness, as a result of the choices or circumstances of their parents.

Such an impact is profoundly unjust."

The letter was signed by the bishops of Bath and Wells, Blackburn, Bristol, Chichester, Derby, Exeter, Gloucester, Guildford, Leicester, Lichfield, London, Manchester, Norwich, Oxford, Ripon and Leeds, St Edmundsbury and Ipswich.