David Cameron has made a highly personal defence of laws which allow the late abortion of babies with disabilities.

The Tory leader insisted it would be 'wrong' to prevent a mother terminating a pregnancy on such grounds.

He said he would 'not want to change' existing laws that permit abortions after the 24-week limit if tests show the baby is likely to be seriously handicapped.

Heartfelt: The Tory leader with his son Ivan, who has cerebral palsy

The issue is extremely sensitive for Mr Cameron because his six-year-old son Ivan was born with a severe form of cerebral palsy and epilepsy and needs 24-hour care.

He had been challenged over his support for the law, which pro-life MPs are seeking to amend through a Bill currently before Parliament.

They want to restrict the type of conditions for which these late abortions can be performed.

As there is no medical definition of 'serious disability' - some doctors have performed late abortions for treatable conditions such as a club foot or cleft palate.

Under the law as it stands, they could perform them at up to 39 weeks.

Speaking to voters in Barrow-in-Furness, Cumbria, Mr Cameron said: 'In the case of parents who have medical evidence that they may have a very disabled child, I would not want to change that.

'I am speaking as someone, I mean, I've got a six-year-old boy who is severely disabled, has cerebral palsy and is quadriplegic and he's a sweet boy, he's a lovely boy.

'It is though incredibly tough bringing up disabled children and I don't want to kind of put myself in the position of saying to other parents you've got to go ahead and have that child or you can't have an abortion or you can do this or you can't do that.

'Personally, Ivan, he's brought incredible things to my life but it is an enormous challenge and I don't think it's right to sort of tell other parents if you hear that you've got a very disabled child on the way, that actually doing something about it isn't an option. That's my view.'

The Tory chief spoke out at a 'Cameron Direct' public meeting after he was asked by an audience member why he opposed 'reversing the discrimination' against unborn children who are disabled.

Mr Cameron, a father of three, has already voted to reduce the abortion limit for healthy babies to 20 weeks from the current 24  -  a move defeated in Parliament in May.

However, the issue of disabled babies will resurface when the Human Fertilisation and Embryology Bill returns to the Commons in the autumn.

Last year, there were more than 200,000 abortions in England and Wales, up from 175,000 in 2002.

More than 95 per cent are carried out for so-called 'social' reasons.

Some 2,000 abortions a year are on grounds of disability. Of these, more than 100 are performed after 24 weeks.

In one region, the South West, 117 babies with club feet, cleft palates, or webbed or extra fingers and toes were aborted between 2002 and 2005.

Across the country, more than 400 pregnancies a year are terminated because of Down's syndrome.

Jim Dobbin, chairman of the all-party Parliamentary pro-life group, described Mr Cameron's remarks as 'shocking'.

The Labour backbencher said: 'This is an equality issue. His statement allows abortion up to birth for the disabled and this sends out a horrifying message to people with disabilities.

'This is telling people with disabilities that they have fewer human rights than people without disabilities.

'Many people with severe disabilities have contributed greatly to humanity.'

John Smeaton, director of the Society for the Protection of Unborn Children, said: 'Here you have a major political figure who could be in a unique position to raise the issue of discrimination against the disabled and he has completely out-manoeuvred himself by adopting this extraordinary position.'