Professor Colin Blakemore, former Head of the Medical Research Council, said:

"I hope that this decision to allow a free vote will take some of the heat out of this issue. However this makes it even more important that MPs should be fully and accurately informed about the science underpinning the bill. I also hope that this announcement takes the focus away from a political row over a free vote and back onto the evidence on which politicians will need to consult their conscience."

Professor Peter Braude, Royal College of Obstetricians and Gynaecologists, said:

"My concern is that this does not create conditions for a free vote - it is simply conversion of a whipped vote for a government bill which has been significantly debated and amended along constitutional lines in the lords, to one which carries a three line whip from the Catholic Church."

Alistair Kent, Director of GIG, Genetic Interest Group, said:

"As representatives of patient organisations we welcome the decision to give MPs the opportunity to vote according to their conscience. However they should remember that in a recent poll 79% of the public indicated that they see this embryonic stem cell research as ethically desirable and scientifically necessary. In exercising their conscience, MPs should not seek to impose their views on this majority. If they cannot support embryo research they should abstain rather than voting against."

Professor Robin Lovell-Badge, Head of the Genetics Division at the Medical Research Council’s National Institute for Medical Research, said:

"I am not against a free vote, as long as the MPs understand what is being proposed in the Bill and why. I am happy to spend time with any MP to explain the science. However, I would also urge them to take on board the views of their constituents, I suspect the majority of whom would support measures that are designed to contribute to the fight against many debilitating genetic diseases and other serious medical conditions."

Dr Stephen Minger, Director, Stem Cell Biology Laboratory, King's College London, said:

"I think one thing we have proved over the past year is that the scientists who want to do research on human admixed embryos are prepared to spend huge amounts of our time explaining to the public and policy makers why we want to do this and exactly what is involved. I welcome any opportunity to debate this further and I hope that Gordon Brown’s announcement today will put an end to the political point scoring and move the debate back to the science and ethics of this research. The potential medical benefits of this research to millions of people with terrible incurable diseases are simply too important for us to allow this debate to descend into a political row."