Solicitors representing the Badger Trust have challenged Natural England to justify its assertions that massively-reduced estimates of badger populations in the proposed culling areas of Gloucestershire and Somerset would not impair the effectiveness of the Coalition's culling policy.

The Trust said a fresh population estimate is now essential because the continuing uncertainty "completely undermines" the likelihood of proving that 70 percent of the badger population in an area had been killed as stipulated by the Coalition. The trial culls are set to be carried out this summer to inform the government's bovine TB eradication policy, which currently includes culling badgers.

Although free-shooting badgers to test the Defra's chosen methodology was due to commence in Gloucestershire and Somerset last year, in October culling trials were abandoned at the eleventh hour when muddled counting meant badger numbers in the trial areas were deemed too high for the farmers' consortia to press ahead with killing.

The latest Natural England estimates point to a reduction in badger numbers.

Badger Trust chair David Williams said earlier this week that "If killings had gone ahead last year as originally planned shooters would have been trying to kill more badgers than now seem to exist. We understand an independent oversight panel has recommended yet another population survey, and our lawyers are asking for a copy of the advice under the Environmental Information Regulations 2004. None of the population estimates seem to have been obtained through a sufficiently consistent approach and we have absolutely no confidence that the latest are any more reliable than the two earlier ones, including those given to MPs by the former farming Minister Mr James Paice in 2011."

On October 18^th 2012, the former farming minister said, "We anticipate that about 1,000 to 1,500 badgers would be killed, as a total over the four years [of the policy], for every 150 sq km area." According to the Badger Trust, a central figure of 1,250 per 150sq km applied to the two pilot areas, which total 567 sq km, would have meant the deaths of 4,725 badgers over four years. The next estimate, published in October last year, would have meant at least 6,632 kills in the first year alone, but the latest figures – threatening at least 4,937 deaths – show a marked drop.

In response, a Natural England spokesperson said, "Natural England has received a letter from lawyers acting for the Badger Trust lawyers and will respond accordingly. The new badger population estimates are based on a wide range of robust evidence, including genetic data from hair trapping and information from sett surveys. The method used has been peer-reviewed and assessed by an independent auditor to ensure we have the best estimates possible."