Stephen Hawking, the world's best-known living scientist, has attacked "reactionary" forces in Europe and America which are trying to ban research into stem cells from human embryos.
Professor Hawking, who suffers from motor neurone disease, has criticised President George Bush and European governments who want to stop the funding of research with embryonic stem cells, which promises to revolutionise the treatment of many incurable conditions.
His attack comes on the day that an attempt will be made in Brussels to prevent any money from the European Union's €54bn (£37bn) science budget being spent over the next seven years on research into human embryonic stem cells.
Germany is leading an attempt to change the way the EU science budget can be spent by individual member states. The plan to block stem-cell research has been bolstered by Mr Bush's use of a veto last week which prevents US federal funds being spent on research into embryonic stem cells. "I strongly oppose the move to ban stem-cell research funding from the European Union," said Professor Hawking, who holds the chair in mathematics at Cambridge University that was once held by Sir Isaac Newton in 1663.
"Europe should not follow the reactionary lead of President Bush, who recently vetoed a bill passed by Congress and supported by a majority of the American people that would have allowed federal funding for stem cell research," he said in a statement to The Independent. "Stem cell research is the key to developing cures for degenerative conditions like Parkinson's and motor neurone disease from which I and many others suffer," he said.
Stem cells are sometimes described as "mother cells" because they can give rise to any one of the many dozens of specialised cells and tissues of the body. Scientists hope to use stem cells from spare IVF embryos to grow specialised cells that can be transplanted into the body as a tissue-repair kit for the vital organs.
President Bush and some religious authorities, notably the Catholic Church, argue that the microscopic, four-day-old embryos from which stem cells are derived are potential human lives. They believe it is immoral to take stem cells from any human embryo even for the purpose of saving lives because the process involves the destruction of embryos.
But Professor Hawking dismissed these objections, saying that banning stem cells from human embryos is equivalent to opposing the use of donated organs from dead people.
"The fact that the cells may come from embryos is not an objection because the embryos are going to die anyway," he said. "It is morally equivalent to taking a heart transplant from a victim of a car accident."
At an EU council of ministers meeting today, Germany, Austria, Poland, Slovakia, Slovenia, Lithuania, Luxembourg and Malta are preparing to vote in favour of a change to the way the EU science budget can be spent.
At present individual member states can decide for themselves whether the funds can be used for research into stem cells that have been derived from spare IVF embryos. Germany, however, wants to end this principle of "subsidiarity" - the right of members states to make their own decisions on the issue.
Lord Rees of Ludlow, the president of the Royal Society, has written to Lord Sainsbury, Britain's science minister, in support of the existing arrangements which allow European funds to be spent on embryonic stem cells. "Last week the United States decided to stay in the slow lane on stem cell research, hindering the global race to develop therapies that could benefit millions of people," Lord Rees said. "It now appears that some countries wish to force the EU as well into the slow lane."
Ireland, Italy, Spain and France, where the Catholic Church is strong, have not so far opposed the deal on the table. That is because this plan says that EU-funded stem cell research would not take place in countries which ban the practice because national rules could not be overridden.