People for the Ethical Treatment of Animals (PETA), one of the largest international campaign groups, says it does not see how the ban cannot help to forward the cause of those who seek an end to all animal experiments.

Andrew Butler, the group's UK representative, said the cosmetics ban was the first time ingredients had entered into the discussion.

"Previously, restrictions only concerned finished cosmetic products. The same kind of ingredients are used in household and some pharmaceutical products," he said.

Poor model

PETA believes there is no moral, ethical or scientific reason to continue using animals in medical research.

"They are a very poor model for human disease and for learning how substances react in the human body. You cannot extrapolate from humans to animals because they metabolise things differently," said Mr Butler.

Most UK animal experiments are on rats and mice, but some involve other animals

He says only about 10% of laboratory experiments which work using animals have the same success in humans.

"Over 50% of all drugs on the market have to be withdrawn or relabelled because they have side effects on humans," he added.

PETA says that products made using human cells are half as toxic as those using animal cells.

It also believes money spent on animal experiments could be spent on disease prevention instead of being poured into research on new drugs which increase drug company profits.

Mistaken

However, the Imperial Cancer Research Fund (ICRF) says animal rights campaigners are "mistaken".

It calls itself a pioneer in developing non-animal research techniques and spends only 2% of its research budget - £1m in 1997/98 - on animal testing.

A quarter of that is spend on breeding the animals and looking after them.

It says this "minimum amount of animal work" is crucial.

"The argument that research with animals tells us nothing because animals are different from humans is not valid," it says.

"There are obvious differences, but the biological similarities are enormous. We would never claim animals are the perfect model for humans. However, they are the best we have."

Enormous debt

The ICRF says animal testing has helped in most, if not all, modern cancer treatment, from developing new drugs to understanding how radiation works.

"Today more than half the 1,300 children who develop cancer every year in the UK can expect to be cured," it says.

The ICRF says animals have helped develop radiotherapy treatment for cancer

"The figure is as high as 90% for some cancers such as Hodgkin's disease. Thirty years ago only one child in every 100 survived.

"The advances in radiotherapy, drug treatments and bone marrow transplantation which have made this success possible owe an enormous debt to animal research."

The ICRF says PETA's argument about funding prevention does not show the whole picture.

It says prevention is important, but in many cases scientists are not sure of all the causes of cancer, which means more research is needed.

Three licences

About 2.3 million mice and rats are used in the UK each year in medical research.

The UK allows research on mice, rats, guinea pigs, hamsters, rabbits, cats, dogs and primates, but cats, dogs and primates require special justification.

Research on chimpanzees, orang-utans and gorillas has been banned in the UK for around 20 years.

The UK first passed legislation on the use of animals in 1876 with the Cruelty to Animals Act.

The most recent current legislation on the use of animals in medical research is the Animals (Scientific Procedures) Act 1986.

Under this, scientists must obtain three licences before they can carry out research using animals.

To get the go-ahead for research, scientists have to justify that any potential harm to the animals is outweighed by the possible benefit to humans.

Benefits

According to Seriously Ill for Medical Research (SIMR), an independent campaign group supporting the use of the humane use of animals in research, only 5p in every £1 spent on medical research goes on animal experiments.

The rest is spent on computer studies, test tube experiments and studying people.

"The benefits far outweigh the costs," says SIMR.

Animal research has been used to develop vaccines against diseases such as smallpox, polio, mumps and measles.

Animals were also used to develop chemotherapy and radiotherapy, used to fight cancer, and for creating new antibiotics as well as research into genetic diseases, disorders of the immune system, heart disease and a range of other diseases, including Alzheimer's Disease.

Cell growing

However, it is likely that recent scientific breakthroughs may eventually mean some reduction in the future use of animals in medical research.

Earlier this month, US scientists described how they had isolated and grown human embryonic stem cells for the first time.

Their experiments could lead to a limitless supply of human tissue for transplantation.

The stem cells are the parent cells for all the tissues in the body.

If the way the cells develop can be controlled it could mean scientists will be able to grow everything from heart muscle to bone marrow and brain tissue.

The scientists believe the cultured cells will give pharmaceutical companies new ways to test the effectiveness and safety of drugs.

PETA says the breakthrough could mean scientists will be able to grow human organs in the future.

This could mean they will not have to use animal organs.