The first licence for a pilot cull of badgers in a bid to tackle TB in cattle is due to be issued this afternoon, Natural England has said.
The first cull will now go ahead in Gloucestershire, a hotspot for the disease.
Animal welfare and wildlife campaigners have opposed the cull, which farmers say is necessary to tackle TB in cattle because badgers spread the disease to livestock, but lost their fight in the High Court.
The cull, which is being paid for by the farmers taking part, will allow the shooting of free-running badgers.
The Government said 26,000 cattle were slaughtered in 2011 as part of TB controls. In the South West almost a quarter of farms were under movement restrictions last year.
Controlling the disease has cost the taxpayer £500 million in the past decade, and costs could spiral to £1 billion over the next 10 years without action, the Environment Department (Defra) said. An outbreak on a farm costs a farmer around £12,000 and the taxpayer £22,000, Defra estimates.
Under the plans for the cull, groups of farmers will pay for the killing of thousands of badgers over an area of 150 square kilometres for four years, costing £200 per square kilometre a year.
A long-term study found that culling over a number of years over a large scale could reduce the incidence of TB in cattle herds by 16%.
But opponents of the cull say it will not have a significant effect on tackling the disease in livestock and are calling for other options, such as developing vaccines.
Wildlife campaigners, including Springwatch's Simon King, started a petition in a bid to get the cull axed. They say the science, including Defra's own research, shows that a cull will not be effective.
Today Chris Packham called the issuing of the licence "shameful" and "unforgiveable".
2 pm today will herald the darkest day for Badgers in Britain and the most shameful for us naturalists and wildlife lovers .— Chris Packham (@ChrisGPackham) September 17, 2012
I feel sick that the science has been forsaken and that Badgers will be scarificed for our stupidity and selfishness . Its unforgivable .— Chris Packham (@ChrisGPackham) September 17, 2012
Shadow environment secretary Mary Creagh said: "The Government is pressing ahead with a badger cull despite their own official advice that it will cost more than it saves, put a huge strain on the police, and will spread bovine TB in the short term as badgers are disturbed by the shooting.
"It could lead to badgers in cull areas being wiped out totally, in contravention of the Bern Convention. Ministers should listen to the scientists and can this cull which is bad for farmers, bad for taxpayers and bad for wildlife."