Research watchdogs were under pressure today not to give a team of scientists in the North-East permission to clone human embryos.

A group of experts opposed to therapeutic cloning is urging the Human Fertilisation and Embryology Authority (HFEA) not to grant a licence allowing the research to go ahead.

The application from Newcastle University is likely to be on the agenda at a meeting today of the HFEA's Research Committee.

Although the authority will not confirm that the proposal is being considered, the scientists were told to expect a decision in June.

Experts from the HFEA have also inspected the laboratories at the Newcastle biotech centre where the work is due to take place.

Today the anti-cloning pressure group Human Genetics Alert said it had written to HFEA chairwoman Suzi Leather asking her to reject the application.

The letter was signed by HGA's director, molecular biologist Dr David King, and six other scientists and ethical experts.

None of the signatories are ''pro-life'' campaigners, said HGA.

In the letter they argue that the planned research is irresponsible, unethical, scientifically weak, unnecessary and politically motivated.

Dr King said: ''This research is a waste of public money, and crosses important ethical lines for the first time.

''It is very unlikely to produce anything medically useful, but it will be a great help for those who want to clone babies.

''It looks like scientists trying to find a use for cloning, so the United Nations won't ban it. We don't believe that embryos are people with rights to life, but neither is it right to create them as mere raw material for research.''

Cloning to create duplicate human babies is outlawed in Britain but therapeutic cloning has been legal since 2002.

It involves cloning embryos and harvesting stem cells from them that could in future be used to treat a wide range of diseases.

The embryos are destroyed before they are 14 days old and never allowed to develop beyond a cluster of cells the size of a pinhead.

Last month the Stem Cell Group at the International Centre for Life in Newcastle applied for a licence to permit human cloning as part of its research programme.

The eggs used would be donated by couples undergoing In-Vitro Fertilisation treatment.

Cloned embryos can be created by replacing the nuclei in human eggs with others from the skin tissue of adult donors. The eggs are then stimulated so they divide, as if they have been fertilised.

Stem cells taken from human embryos have the potential to become any kind of tissue in the body, including bone, muscle, nerves, and organs.

Scientists hope to use them to fight diseases that at present are incurable.

The Newcastle team plans to investigate creating insulin-producing cells that can be transplanted into diabetic patients.

Other future applications could involve the treatment of brain diseases such as Alzheimer's and Parkinson's, or damaged hearts.

The scientists are led by Dr Miodrag Stojkovic, from the Institute of Human Genetics at Newcastle University, and Professor Alison Murdoch, from the Newcastle Fertility Centre.

Dr Stojkovic's group has already generated a line of embryonic stem cells now housed at the new UK Stem Cell Bank near Potters Bar, Hertfordshire. Earlier this year, researchers in South Korea announced that they had produced the first human cloned embryos.

Professor Murdoch, of Newcastle University, said: ''This is a first for the UK and we should be very proud of it.

''We are looking at five to 10 years before we can even begin to think about having readily available cures. But we have got to start somewhere and this is so promising we can't afford not to let it happen.''

Prof Murdoch said the plan differed from reproductive cloning although the science behind it was the same.