Bids to ban the use of hybrid human-animal embryos and the creation of "saviour siblings" have failed.

The decisions follow intense debate in the Commons on the Human Fertilisation and Embryology Bill - the biggest shake-up of law in this area for 20 years.

A bill to ban the creation of "saviour siblings", or children genetically matched to help treat a sick older brother or sister, was defeated by 342 votes to 163.

MPs voted 336 to 176, a majority of 160, against a move to ban the use of hybrid human-animal embryos for scientific research, a move led by Tory former minister Edward Leigh.

The Commons also rejected a bid to ban the use of so called "true hybrids" using the sex cells of a human and an animal. Voting was 286 to 223 -a majority of 63.

Controversial attempts to reduce the abortion time limit will be debated on Tuesday.

Mr Leigh said the use of "admixed" embryos, using genetic material from both humans and animals, would cross an "entirely new ethical boundary," and turn the UK into a scientific "rogue state".

The embryos created would have to be destroyed after 14 days, but scientists hope stem cells can be harvested and used to create brain, skin, heart and other tissue for treating diseases.

Mr Leigh warned it was a "step too far" adding: "In many ways we are like children playing with landmines without any concept of the dangers of the technology that we are handling."

But Labour's Chris Bryant (Rhondda), a former Anglican curate, compared Mr Leigh's arguments to those used by church leaders against the smallpox vaccine.

"They were wrong and I think you are wrong today," Mr Bryant said.

All the main parties allowed MPs a free vote on the creation of the "admixed" embryos and on the creation of so-called "saviour siblings".

Earlier, Prime Minister Gordon Brown praised "hybrid" techniques as an "inherently moral endeavour" and said they could save millions of lives.

He urged MPs to help "ourselves and future generations" by passing the measures in a free vote.

But the Roman Catholic Church has branded the use of hybrid embryos as "monstrous" and says tinkering with life in this way is immoral.

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