British scientists are planning a ground-breaking research project to create synthetic human blood from embryonic stem cells, it has been disclosed.

The results could provide an unlimited supply of blood for emergency transfusions free of the risk of infection.

It could revolutionise blood transfusion services, which currently rely on a network of human donors to provide a constant supply of fresh blood.

The three-year project will be led by the Scottish National Blood Transfusion Service and includes NHS Blood and Transplant and the Wellcome Trust, the world's biggest medical research charity.

The artificial blood will be made from the stem cells of human embryos left over from IVF treatment.

Researchers will test the embryos to find those that are genetically programmed to develop into the "O-negative" blood group.

This is the universal donor group, whose blood can be transfused to any patient without the fear of tissue rejection.

The rare blood group, which is applicable to only 7 per cent of the population, could then be produced in unlimited quantities because of the embryonic stem cells' ability to multiply indefinitely.

The objective is to stimulate the cells to develop into mature, oxygen-carrying red blood cells for emergency transfusions.

Such blood would have the benefit of not being at risk of being infected with viruses such as HIV and hepatitis.

The SNBTS is expected within weeks to sign an agreement with the Wellcome Trust for a grant to fund the multi-million pound research project.

A spokeswoman for the SNBTS confirmed that the research project was to go ahead but said that no further comment could be made because it was bound by a confidentiality agreement with the Wellcome Trust.

According to The Independent, the project will be led by Professor Marc Turner, of Edinburgh University, the director of the Scottish National Blood Transfusion Service.

Professor Turner has been involved in studies examining ways to ensure donated blood is free of the infectious agent behind variant CJD, the human form of "mad cow" disease.

Last year, Advanced Cell Technology, a US biotechnology firm, claimed it had produced billions of functioning red blood cells from embryonic stem cells.

However, US projects have been delayed due to funding problems as a result of the ban on embryonic stem cell research introduced by the Bush administration, which Barack Obama has since overturned.