The Badger Trust has issued a "pre-action protocol letter" over the proposed eight-week extension of the badger cull in Gloucestershire.
An extra three weeks was granted in Somerset, where 60% of the badger population was culled.
A "pre-action protocol letter" to Natural England and the Treasury Solicitor for the Secretary of State Secretary of State for the Department for Environment, Food and Rural Affairs has been actioned by the Trust.
It is the first stage in seeking a judicial review in the High Court, the letter states:
We consider that the decision to extend the cull in Somerset was unlawful, particularly in the light of those documents.
But given that we have only just seen them and given the relatively shorter extension there, we have advised our clients that it would not now be practicable (given the court process) to seek injunctive relief to prevent it.
But that is not the case in relation to the contemplated decision in relation to Gloucestershire not least because of the much longer extension (eight weeks) being sought (and not yet granted) and the fact that our clients have now seen the nature of the arguments being relied on to justify further culling.
More top news
The iconic Shaun in the City figures are being auctioned off on Thursday. It's expected to raise millions for Bristol Children's Hospital
Mike Ford is the favourite to replace Stuart Lancaster - but says his focus is on getting disappointed England players back at Bath Rugby.
Family and friends of a missing man from Swindon took to the streets today in a desperate effort to find him.