The House of Lords has backed a government plan to allow the cloning of human cells for medical research.

Over 40 peers had registered to speak in Monday's debate on the Human Fertilisation and Embryology (Research Purposes) Regulations 2000, which were approved by MPs last month. Some peers accused the government of pushing through the changes using "undemocratic" tactics on what amounts to a major "moral" issue.

The Bill makes provision for the circumstances in which a man is to be treated in law as the father of a child where the child has resulted from certain fertility treatment undertaken after the man's death. It also contains legislation changing the law to allow researchers to carry out a limited "therapeutic cloning" to create a genetically identical embryo of a patient.

Under the existing laws passed in 1990, scientists are allowed to experiment on embryos up to two weeks old for fertility research. Scientists argue the law should be extended so embryos can also be used to find cures for diseases such as cancer, heart disease and Alzheimer's.

Catholic peer Lord Alton of Liverpool tabled an amendment to legislation passed by MPs last month calling for the order to be sent to a select committee before it is approved. If passed it would have delayed changes to the Human Fertilisation and Embryo Act meaning it would not become law before the election.

Lord Alton told peers: "One does not have to believe in the sanctity of human life, or that life begins at fertilisation, to be concerned about the general commodification of life. Every generation is tempted by the seductive and tantalising prospect of universal happiness as a trump over all other values and principles, but human dignity must always be defended against the abuse of scientific techniques."

The Archbishop of Canterbury wrote to all peers urging them to consider the "huge philosophical and ethical implications of these developments" and a letter published in the Telegraph from Cambridge medical students warned of the "potentially devastating" consequences of cloning.

Lord Dubs said: "I would ask this question: if we do not pass these regulations today - if we delay them as suggested in the amendment of the noble Lord, Lord Alton - how do we say to sufferers of Parkinson's, cancer, diabetes, spinal cord injury, severe burns, Alzheimer's, MS and so on, 'No. We did not have enough information. Despite the many reports and investigations that have taken place, we did not want to make a decision because we wanted more information'?"

Lord Winston, who holds several patents into cell research and is one of the world's leading experts in the field, made an impassioned speech. "As I speak this evening I recognise that I have a great moral responsibility because I am the only Member of your Lordships' House who is involved in, and has an intimate understanding of, this research and is daily confronted with the issue of human experimentation.

He said: "Essentially, the debate is about transplantation and regeneration. In order to be effective, stem cells need to be transplanted. Some noble Lords are also aware that there is a possibility that some tissues can regenerate by controlling the genetic influences. It is clear from every biological investigation that the only way to do that is to look at embryological knowledge, most of which can undoubtedly be derived from animals."

Professor Richard Gardner, chairman of the Royal Society working group on therapeutic cloning, welcomed the result saying: "This result will allow scientists in the UK to stay at the forefront of this very important and exciting field of research, and demonstrates that the UK is leading the rest of the world in the regulation of this work. It means that stem cell research can be carried out in British universities in a way that is fully accountable and transparent."

The legislation, tabled by Tony Clarke with support by Joe Ashton, Peter Bottomley and Dr Evan Harris received its first reading on January 17 and returns to the Commons for its second reading on March 23.