Badger Trust and Wild Justice have announced they have sent a pre-action protocol letter over the government's badger cull.
The letter has been sent to Natural England and the Defra Secretary in a bid to stop the supplementary badger cull programme.
Both wildlife organisations say they are "continuing their fight" to stop culling by jointly instructing solicitors to challenge the government's decision.
This action could lead to the groups to call for a full Judicial Review. Natural England has been given until 15 July to respond and to halt the supplementary cull.
Supplementary licences for badgers to be culled have been given the stamp of approval for 17 existing and nine new zones.
Culling started on 1 June, with Badger Trust estimating it could lead to the death of up to 30,000 badgers by 2026.
Peter Hambly, executive director of campaigning group, said: “We will continue to fight for badgers and stop this ineffective and unethical badger cull immediately
“Badgers continue to be killed, despite Natural England’s own scientific advice to stop the supplementary badger cull that started in June 2024.
"More badger lives are being wasted, with Natural England’s scientific advisor saying the present cull is not the way forward. The cull must end now.”
