The first licence allowing farmers in England to shoot badgers in an attempt to reduce cattle TB has been issued.
The licensing body, Natural England, said the cull would start in weeks in Gloucestershire, where cases are high.
Ministers are pressing ahead with plans to cull badgers in two areas of the South West, amid pressure from farmers.
The science behind the culls is uncertain; a decade-long scientific trial of badger culling concluded there were only modest benefits.
Evidence shows that some wild badgers can become infected with the bacteria that causes bovine TB, and pass the infection on to cattle.
Scientific estimates suggest that culling badgers in areas where bovine TB is prevalent could reduce the number of new cases of TB in herds by 16% over 9 years, said Defra.
Natural England issued the first licence for Gloucestershire on Monday, while a second, for Somerset, is still being assessed.
The licenses will allow farmers to shoot up to 70% of badgers in the pilot zones.
The first cull is expected to begin with weeks in west Gloucestershire, within a defined area which is being kept secret.
The final go-ahead depends on farmers confirming they have sufficient funds for the cull.
Animal welfare and wildlife campaigners have opposed the cull, which will allow wild badgers to be shot by trained marksmen when the animals venture out of their setts at night. The Badger Trust lost a fight challenging the legality of the cull in the High Court last week, but is looking at the possibility of further legal action.
Defra says action is necessary to protect cattle from bovine TB, which leads to the slaughter of thousands of cattle each year.
Defra Minister David Heath said: "Our priority has always been to ensure that any culling of badgers is carried out in a safe, humane and effective way.
"The licence for Gloucestershire issued by Natural England today meets all the strict criteria we imposed, and the pilot in this area will help us assess the effectiveness of controlled shooting before we look at a wider roll out to control the spread of bovine TB in cattle.
"No one wants to kill badgers but the science is clear that we will not get on top of this disease without tackling it in both wildlife and cattle."
Plans to begin culling in Wales were recently abandoned in favour of a vaccination policy. There are no proposals to cull badgers in Scotland, where TB incidence is generally low.