A donor has been found for a five-month-old boy who will die unless he has a liver transplant, it was revealed today.

Lennox Nicholson is undergoing the life-saving liver transplant at the world famous St James's University Hospital in Leeds to save his young life.

Last week, parents Simon Nicholson and Amy Robinson made a desperate appeal for help and said their son had just days to live unless he had the operation.

A spokesman for the hospital, known as ''Jimmy's'', said a donor liver had been found for Lennox and the tot was having the transplant today. Mr Nicholson, 21, and Miss Robinson, 20, from Guisborough, in Teesside, were at the hospital awaiting news of the operation, which is expected to last up to 10 hours.

Doctors will use half of a donated adult liver to save Lennox and the other half would be used to save another person's life.

Lennox's grandmother June Nicholson was told the news of the transplant by her son.

She told BBC News Online: ''We just wanted to open the door and shout out and tell everybody. We are very nervous but also very happy ''We were warned there's always a chance it can get to the table and not be suitable, but we have heard no more so we are hoping the operation is going ahead.

''Hopefully this potential donor has turned out to be suitable.''

When Lennox was born on June 21, weighing 7lb 1oz, at Middlesbrough's James Cook University Hospital, he appeared to be healthy. But within weeks he developed jaundice and chronic liver problems.

An eight-hour operation found his bile ducts were completely blocked and the only way to save his life was to give him a transplant.

On Saturday, Mr Nicholson said he and his partner said they had not given up hope that a donor would be found in time to save Lennox's life.

''We go to bed every night with butterflies thinking this will be the night he will get his transplant,'' he said.

''We have a pager with us at all times if we ever leave the hospital in case something happens. We're both confident it will.''

A spokesman for The Leeds Hospitals NHS Trust said: ''Lennox is currently undergoing a liver transplant at St James's Hospital.

''The operation involves a section of adult liver and is not expected to be finished until later this evening.

''Lennox's parents have requested that they be left alone until he has begun to recover from the operation.

''No further statement will be issued before tomorrow.''