The government would resist protesters who used blackmail and intimidation to wreck legitimate research, Blair said in an attack on activists opposed to genetic modification in agriculture, experiments on animals and research into human embryos.
Blair acknowledged "legitimate concerns" about developments such as GM crops and embryo research, but he said scientists had to be allowed to carry out research in order to establish the facts before any rush to judgment.
"Let us get to the facts and then judge their moral consequences. There is a danger that, almost unintentionally, we become anti-science," he said.
Developments in biotechnology, which could see cures for diseases such as cancer, diabetes and heart disease, depended upon scientists being able to carry out research, he said.
"Sometimes it is controversial, as with GM crops or animal testing. Such research is, rightly, strictly regulated, but this government will not tolerate blackmail, even physical assault, by those who oppose it.
In a warning to the scientific establishment, Blair said scientists needed to develop a "far more considered rational dialogue" with the public if they were to accept the need for continuing research and development.
He emphasised the economic importance to Britain of scientific development, with the European biotechnology market expected to be worth 100 billion dollars by 2005 and employing up to three million people.
But Greenpeace executive director Peter Melchett - one of 28 protesters cleared by a court of criminal damage after they wrecked an experimental maize crop - said Blair should adopt a more questioning approach.
"Worshipping slavishly and unthinkingly at the seat of every new scientific fad is more damaging to science than the healthy, questioning scepticism that most other countries show towards untried, unpredictable and uncontrollable technologies like GM food," he said.
Laboratories involved in experiments with animals have regularly been the attacked by animal rights activists in Britain and the scientists who work their subjected to intimidation. There has also been strong objection into the use of human foetuses for research.
(klei/dpa)
