The BBC's Ashley Gething: "Farmers cannot afford another health threat"

Campaigners say the Ministry of Agriculture, Fisheries and Food's experiment to kill 20,000 badgers in an attempt to establish whether they pass tuberculosis onto cattle is against European law.

They will spell out their objections at a meeting in Strasbourg of the Standing Committee of the Bern Convention - Europe's longest standing wildlife treaty.

Farmers fear TB could be the next BSE

Conservation Officer for the National Federation of Badger Groups, Elaine King, accused the government of "failing to meet its international obligations on wildlife protection".

"Our legal advisors are confident that the government's badger culling experiment is a clear breach of Articles 7,8, and 9 of the Bern Convention."

These rules require governments to take legal and administrative steps necessary to ensure the protection of certain animals, including the badger.

Campaigners say the cull is inconsistent with the convention.

There is also a ban on traps where it is likely to lead to the local disappearance of a protected species.

Traps will be laid then the badgers will be shot

"The government is planning to trap badgers in cages, before shooting them.

"The experiment will therefore result in the local extinction of badgers in large areas of south-west England and southern Wales and badgers will be prevented from recolonising in most of these areas for at least five years," said Dr King.

The government's proposals to kill badgers were unveiled earlier this year in response to a rise in TB in the UK's cattle herd.

Current levels of the disease in cattle stand at about 0.4%, but that figure is rising rapidly.

Farmers fear that incidents of the disease may exceed 2% - which would mean a total ban on the export of beef products.