The ideological divide between campaigners and scientists was exposed again last night in the wake of figures showing experiments on animals in the UK rose by 41,300 last year to 2,896,000.
While some hailed a "golden age of medical discovery", activists criticised the Government's "permissive, head-in-the-sand attitude" to testing.
The 1.4 per cent increase on the previous 12 months was revealed in Home Office statistics.
Primates, dogs, cats and horses were used in under one per cent of procedures, with the majority of species used being mice, rats and other rodents (85 per cent).
The remainder involved primarily fish (eight per cent) and birds (four per cent).
Use of primates went up 11 per cent to 4,650 individual procedures, involving 3,120 animals.
But while scientists and charities asserted the medical need for testing, and the fact it should be taken in context, five members of the British Union for the Abolition of Vivisection (BUAV) dressed as animals at a mock funeral procession at the Home Office.
A spokesman for BUAV, Alistair Currie, said: "Sadly, it's no surprise that numbers have gone up again.
"This Government has no grasp of the problem of animal experimentation.
"Their permissive, head-inthe-sand attitude offers no prospect of the upward trend being reversed, never mind bringing to an end this outdated, inhumane and unproductive practice."
However, a Home Office spokeswoman said the UK's controls on animal use were amongst the tightest in the world, while the Government was "firmly committed to the three Rs" - reducing the number of animals used, replacing animals wherever possible and refining scientific procedures involving animals and improving animal welfare. Minister Joan Ryan added: "Animal research and testing has played a part in almost every medical breakthrough of the last century.
"It has saved hundreds of millions of lives worldwide, and is vital to our NHS. Where animal research is the only option, we will continue to ensure that the balance between animal welfare and scientific advancement is maintained."
And the level of testing in the UK was backed by a raft of scientists and charity heads.
Dr John Parrington, from Oxford University, said the figures had to be placed in the context of research development, with the "slight increase" almost wholly due to an increase in using genetically modified mice.
Jo Tanner, chief executive of the Coalition for Medical Progress said: "We are living in a golden age of medical discovery, from mapping the human genome to finding new cures and treatments for deadly and debilitating conditions. And at the heart of this golden age is the relatively small use of animals."