Defra officials have admitted that the department commissioned 'secret badger gassing trials' last summer, as tensions rise ahead of the resumption of culls in Somerset and Gloucestershire this year.

The government, and its supporters in the NFU, maintain that badger culls are needed to address the reservoir of bovine TB in wildlife. However, the scientific basis for the cull is looking increasingly shaky. Public support, which was never strong, has melted away over the past year as the badger cull has become a by-word for blunder. Failures range from botched population estimates, which were revised three times in the year before shooting began, to missed (self-set) targets even after culling periods were extended by more than 50 percent in both zones.

Gassing was outlawed as a means of killing wildlife in 1982; the method was deemed to be inefficient and inhumane. Last year's badger cull was ostensibly set up to trial the previously untested 'free-shooting' methodology of badger dispatch, but earlier this year the Independent Expert Panel appointed to assess the cull revealed that companies had introduced the more expensive trap-and-shoot method after only two days, in both cull zones and at the public's expense.

Last month, Princess Anne attracted criticism for declaring her support for gassing in an interview with BBC Country File.

Whilst culling was ongoing in the South-West, an investigative report revealed that groups of farmers were gassing badger setts in the region illegally. Groups were found to be using social media networks to arrange illegal 'gassing trials' on at least 14 farms in Southern England.

Government commissioned secret gassing trials

Although environment secretary Owen Paterson acknowledged last year that Defra was conducting "desk-based research" into gassing, in light of the 'pilot' culls' failure on the grounds of both humaneness and effectiveness, Paterson's department revealed in response to a freedom of information request on Thursday that it has been conducting trials using carbon monoxide gas at an undisclosed testing facility to assess the feasibility of gassing badger setts.

In answer to an FOI request, Defra has admitted that since Summer 2013 it has been conducting trials to test carbon monoxide gas dispersal in badger sett structures. No live animals or active setts have yet been used, but wildlife groups have said this reveals a worrying escalation of the department's interest in gassing as a method of killing badgers, particularly as future culls may be carried out without independent oversight.  

Mark Jones, a vet and Executive Director of Humane Society International UK, said, "I am appalled that Defra has secretly been spending public money testing gassing as a potential method of killing badgers. It shows a chilling and arrogant determination by this government to massacre these wild mammals at all costs. Defra's shambolic badger cull last year showed that free shooting is inhumane and won't work and that cage trapping is hugely expensive, so now they're looking at gassing these protected wild mammals in their setts. Where will this insanity end?"

"As a vet I am shocked that DEFRA is even considering the possibility of inflicting such a cruel and discredited killing method on England’s badgers, especially when it is specifically prohibited by the Bern convention. It has already been established beyond any reasonable doubt that badger culling is unscientific, unjustified and unnecessary," Jones continued. "Previous gassing studies saw cats, dogs, guinea pigs and monkeys enduring anything from tremors and vomiting to severe lung pain, heart attack, suffocation, coma and death. Sub-lethal exposure to carbon monoxide, the gas Defra has been studying for the past year, caused vomiting, urination and defecation in dogs, and limb paralysis, blindness and deafness in monkeys. The difficulties in delivering gas to complex badger setts mean that many animals will inevitably experience sub lethal exposure, so the potential for animal suffering is huge."

The HSI director added that badger setts may also be used by many other species including rabbits, foxes, otters and some reptiles, which could also be adversely affected by sett gassing, and that gassing could contravene Article 8 of the Bern Convention, which "prohibit[s] the use of all indiscriminate means of capture and killing… includ[ing] 'gassing or smoking out.'"

In Wales, where a proposed badger cull was was rejected following a scientific review in 2012, bTB figures appear to be falling. In the 12 months to the end of February 2014, new herd incidents in Wales fell by 23 percent compared to the previous 12 months, and the number of cattle slaughtered fell by 35 percent from 9,436 to 6,167.

Wales reintroduced a requirement for annual cattle testing in 2008, alongside greater cattle movement restrictions, a zero tolerance of overdue bTB tests, the rapid removal of reactor cattle from herds, and encouraged to farmers to practice risk-based trading.

Ahead of the Defra Secretary's announcement in April that culls would resume in the South-West this year, but would not be rolled-out to new areas, John McInerney, Emeritus Professor of Agricultural Policy at the University of Exeter, said, "It is not the case that the pilot culls were intended to limit the spread of bovine TB. The objective stated quite clearly at the outset was simply to ascertain the effectiveness and humaneness of shooting badgers as a method of culling. There was no intention to determine whether it might limit the spread of the disease because nothing was done to measure the levels of bovine TB either before, during or after the culls took place, and no disease measurement comparisons between the cull area and an area where culling was not happening were made."

Speaking to the Guardian, he added, "Bovine TB… is a disease of cattle and the badger is just an accessory, so badger culling (or vaccination) is just an accessory to the main problem. The control strategy has to be built directly around measures to limit the spread within the cattle population."