A reduction in the legal limit for abortion from 24 weeks would give false hope to the parents of severely premature infants, the public health minister has said.

Ahead of the Commons debate on the Human Fertilisation and Embryology Bill, Dawn Primarolo said that claims by anti-abortion MPs that foetuses are commonly viable at 22 and 23 weeks could mislead parents.

In an interview with the Times, she said such statements suggest that premature babies have a better chance of survival than is really the case.

"I think that the issue is, most importantly, raising hope when the science doesn't indicate that it should be there," Primarolo argued.

"There is a danger of giving hope to desperate parents, who are in difficult enough circumstances anyway, that may not be there for them."

Amendments

The Bill is designed to aid scientific and medical research into embryology.

But Conservative MP Nadine Dorries, who wants to lower the limit on abortions for social reasons from 24 to 20 weeks, is set to table an amendment to the legislation.

Dorries says babies born at 24 weeks are increasingly likely to survive, so it should not be permitted to abort pregnancies at this stage.

However, Labour MP Emily Thornberry told the House Magazine that she was concerned "that there may be attempts to limit access to abortion".

"The bill allowing abortion is now 40 years old and whilst there are many things we could do to improve it, restricting the right of access is certainly not one of them," she said.

Free votes

However any amendments on abortion will be put to a free vote in the Commons.

And Gordon Brown was earlier this year forced to offer an unwhipped vote on three of the main areas of the bill, which has its second reading in the Commons on Monday.

The prime minister said that MPs would be able to vote with their consciences on measures which would allow the use of human-animal hybrid embryos for research, as well as on the issue of "saviour siblings" - creating a child with the correct tissue match to save a sick brother or sister.

MPs will also have a free vote on whether fertility clinics should have to consider a child's need for a father when offering IVF treatment.

But Brown said he expected Labour MPs to back the bill as a whole "because there are so many other changes that I believe are necessary".