An 8% rise in the number of animal experiments performed in the UK has been condemned as indefensible and shocking by welfare campaigners.
The figures for last year, released by the Home Office, include a 22% increase in the number of procedures involving monkeys.
Four million licensed procedures were started in the UK in 2012 - 317,200 more than there were in 2011. Most of the increase was due to the creation of genetically modified (GM) animal "models" which accounted for around half the total.
The Home Office, which regulates animal testing, insisted that experiments on living creatures are only conducted when absolutely necessary and suffering is kept to a minimum.
But animal welfare groups said they were "stunned" and "shocked" by the figures, and accused the Government of breaking its promise to address the issue of animal testing.
Michelle Thew, chief executive of the British Union for the Abolition of Vivisection (BUAV) said: "The Government has failed for a third year on its post-election pledge to work to reduce the number of animal experiments and, as a result, millions of animals continue to suffer and die in our laboratories. This lack of progress is completely unacceptable. We need to see meaningful and lasting changes for animals in laboratories."
A similar statement from People for the Ethical Treatment of Animals denounced the "industrial-scale" breeding of GM animals, many of which were genetically programmed to suffer painful defects. It said: "The Government must keep its promise to reduce the number of animals used in experiments. We want animals out of laboratories and cutting-edge replacements in."
Humane Society International claimed Government spending on finding alternatives to animal testing remained "woefully inadequate", amounting to just 66p for every animal used in a UK laboratory. The organisation said: "Despite a Government pledge to reduce animal experiments and repeated claims that animals are only used when absolutely necessary, millions of mice, monkeys, rabbits, fish, dogs and other animals still suffer in UK laboratories. The excuse that this level of animal use benefits medical research is wearing thin."
The RSPCA pointed out that the number of dogs used in experiments had increased for the first time since 2007, rising from 2,865 to 3,214.
Chief executive Gavin Grant said: "The latest figures are alarming and should serve as a wake-up call to all involved to up their game in the mission to replace and reduce the use of animals in research and testing. We will be asking for an urgent meeting with Lord Taylor, the Home Office minister with responsibility for animal experiments, and with the Department for Business, Innovation and Skills, to discuss this issue which is extremely important to the lives of animals and so many of the public."