But when it was explained that animal tests could lead to cures for childhood leukaemia and AIDS a slim majority, 45 percent, said they would be in favour of it, compared to 41 percent who were opposed.

The swing was 23 percent for women and 21 percent for men.

"The implication is that the public's mind is not made up on these issues," said Robert Worcester, the chairman of MORI.

"Most people are willing to be persuaded, although initially sceptical of the value of animal experimentation," he added.

Britain is a nation of animal lovers. Animal rights campaigners have issued death threats and conducted bombing campaigns against scientists who conduct research on animals.

The poll showed that a majority of people in Britain were prepared to let mice and monkeys suffer in experiments for treatments for life-threatening diseases but fewer thought it was justified in tests to develop new painkillers.

Only one in 20 people said they could condone the death of monkeys to test cosmetics.

MORI questioned 2009 people in their homes in March for the survey.