A bid to bring back the lynx, which became extinct in the UK more than 1,000 years ago, has been rejected by the Environment Secretary.
Lynx UK Trust applied for a licence for trial reintroduction of six Eurasian lynx into Kielder Forest in Northumberland.
The cats were lost from much of Western Europe following the destruction of their habitat but they have been successfully reintroduced in some countries.
Environment Secretary Michael Gove has written to the trust informing it he has accepted the advice of Government conservation agency Natural England not to grant a licence for the scheme.
Mr Gove said the Government remained committed to the reintroduction of once-native species when there are "comprehensive proposals" and clear environmental, social and economic benefits.
Natural England had concerns about the feasibility of the project, including how it would be funded and a reliance on volunteers, he said.
The application did not include an ecological assessment providing assurances the area was suitable for a reintroduction and did not demonstrate sufficient engagement with landowners or local support.
In his letter, Mr Gove said: "Kielder Forest is an area where the Forest Commission has been taking action to manage and restore important habitats and ecosystem functions to enhance biodiversity.
"This has included the release of hundreds of water vole and the removal of mink from the Tyne and monitoring the return and spread of pine martens to understand options for their recovery.
"The area has also seen significant recolonisation by a number of bird species as a result of continued efforts, all of which is positive news."
Opponents, such as the National Sheep Association (NSA), have raised concerns about the losses of livestock and the welfare of the wild animals released into the "busy, industrial forest".
NSA chief executive Phil Stocker said: "We strongly believe this is the right decision on ecological, social and agricultural grounds.
"Today's victory is not just for farmers but for the ecology of the area, the rural community and the farming economy.
"The threat of the lynx against sheep was very real and we could not be happier that this isn't a risk our members will have to face."