What these amendments are simply about is to widen the pool of potential adoptive parents

Alan Milburn

He was therefore offering MPs a vote on allowing unmarried couples to adopt.

Such a move would involve amending the Adoption and Children Bill.

The vote is expected to take place later this year.

Mr Milburn said it would be up to the relevant agencies to decide which people could adopt.

He said no-one had the right to adopt and stressed that at the moment single people as-well-as married couples could adopt.

"It's important when we are considering these amendments - which incidentally I personally support - that we understand that what these amendments are simply about is to widen the pool of potential adoptive parents so that more children that are vulnerable ... have the chance of the stable family life that adoption can bring," he said.

In 1999 gay couple Tony Barlow and Barrie Drewitt spent �200,000 arranging a surrogate birth to an American mother.

They made the move after an application to adopt a child in Britain was rejected, and had twins, Aspen and Saffron.