The Westminster government claims its badger culling policy is ‘science-led policy’ but scientists and experts closely involved in the issue strongly disagree.
Randomised Badger Culling Trial
Most of the science surrounding the role of badgers in the spread of bovine TB in cattle comes from the Randomised Badger Culling Trial commissioned by the then government in 1997, which took 10 years and £50 million of taxpayers’ money to complete. The trial involved killing around 11,000 badgers in designated areas, and the impacts on TB in cattle were compared between these and similar areas in which culling did not take place.
The trial was overseen by a group of independent scientists chaired by Professor John Bourne CBE MRCVS, who drew the following conclusions: 
“…badger culling can make no meaningful contribution to cattle TB control in Britain. Indeed, some policies under consideration are likely to make matters worse rather than better”
“weaknesses in cattle testing regimes mean that cattle themselves contribute significantly to the persistence and spread of disease in all areas where TB occurs, and in some parts of Britain are likely to be the main source of infection… Scientific findings indicate that the rising incidence of disease can be reversed, and geographical spread contained, by the rigid application of cattle-based control measures alone.”
“It is unfortunate that agricultural and veterinary leaders continue to believe, in spite of overwhelming scientific evidence to the contrary, that the main approach to cattle TB control must involve some form of badger population control. It is our hope that Defra will embrace new scientific findings, and communicate these to stakeholders in ways that encourage acceptance and participation.”
Subsequent scientific evidence
Following the ten-year trial, scientists continued to monitor the impact on bovine TB in cattle in the areas in which badgers had been culled. The conclusions drawn included the following:
“Our findings confirm that badger culling can prompt the spatial spread of M.Bovis infection, a phenomenon likely to undermine the utility of this approach as a disease control measure.” 
“…reductions in cattle TB incidence achieved by repeated badger culling were not sustained in the long term after culling ended and did not offset the financial costs of culling.” 
Professor John (now Lord) Krebs, currently Principal of Jesus College, Oxford and Chair of the House of Lords Science and Technology Select Committee, chaired the Independent Scientific Review Group whose 1997 report ‘Bovine Tuberculosis in Cattle and Badgers’  led to the establishment of the Randomised Badger Culling Trial. Professor Krebs has recently been outspoken in his opposition to the government’s policy:
“I would go down the vaccination and biosecurity route rather than this crazy scheme [the government’s plan to allow the culling of badgers] that may deliver very small advantage, may deliver none. And it’s very hard to see how Defra are going to collect the crucial data to assess whether it’s worth going ahead with free shooting at all” (BBC interview September 2012).
“You cull intensively for at least four years, you will have a net benefit of reducing TB in cattle of 12% to 16%. So you leave 85% of the problem still there, having gone to a huge amount of trouble to kill a huge number of badgers… It doesn’t seem to be an effective way of controlling the disease.” (The Guardian Newspaper, July 2011).
Dr Chris Cheeseman, a former Head of Wildlife Diseases at the Central Science Laboratory who spent most of his working life studying the role of badgers in the spread of tuberculosis in cattle, stated:
“This government claims that their policy is science-led but I’m afraid it’s not … [it] could lead to the deaths of — using their figures – up to 130,000 badgers over a few years to achieve an overall, at best, 16 percent reduction in cattle TB. Now there are those of us in the scientific community who actually think it [the cull] will make it worse, and I suggest that’s an unacceptable policy.” (Transcript of an interview in August 2012).
Dr Rosie Woodroffe from the Institute of Zoology, London, a former member of the Independent Scientific Group charged with overseeing and assessing the Randomised Badger Culling Trial, said of the government’s policy:
“I think it is scientifically among the worst options they could have chosen.” (Interview with the Guardian newspaper, September 2010).
Advice to government from its own agencies and scientists
During the government’s consultations on its plans to introduce badger culling, a number of government scientists and agencies have provided comments and advice.
Professor Sir Bob Watson, former science adviser to DEFRA:
“Culling won’t solve the problem nationally [across England]. But farmers in Devon, Cornwall and Gloucestershire are arguing that it can get between a 16% and 20% reduction which they think is significant and that they are willing to pay for… I would say the economics is very close as to whether it is worth it. But the government has made a decision that [it should be tried if farmers are willing to fund it]. The question [then] is: ‘Is it a significant effect? Is it cost effective? Is it socially and ethically appropriate?” (extract from BBC interview September 2012).
Natural England, the designated licensing authority for the proposed badger culling operations:
“While it is reasonable to assume that replicating the RBCT approach would deliver similar benefits in a future cull, it is far from certain that these benefits could be delivered via the farmer and landowner led approach that has been proposed” 
Impacts on badger populations
The government has said its plans will ensure that badger populations will be protected in cull areas. Indeed it is obliged under its commitments to the Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention)  to prevent ‘serious disturbance’ to badger populations, and keep them ‘out of danger’. However, scientists and government agencies have expressed concerns about the impact the government’s policy could have on badger populations.
These include former Independent Scientific Group members Prof. Crystl Donnelly and Dr Rosie Woodroffe:
“…culling too many badgers risks local extinction, contravening the Bern Convention… culling [by the government’s proposed methods]… could eradicate anywhere between 51% of the resident badger population [risking an increase in cattle TB] and 100 per cent [risking a breach of the Bern Convention].” 
And Natural England, the designated licensing authority for the proposed badger culling operations:
“Reducing the badger population to the extent and on the scale permitted under this policy has not previously been sanctioned for any protected native mammal species in modern times… the estimated national [badger] population could be reduced by up to 30% and the population in the west and south-west regions by up to 50%… there is no simple and cost effective method of accurately measuring badger population numbers at the spatial scale proposed under this policy, nor will it be possible to accurately measure changes in abundance following culling… because the evidence-base is imprecise, neither upper limits on badgers licensed to be culled nor adjustments based on monitoring during control operations can guarantee badger survival locally… it is our view that the local disappearance of the badger in some areas cannot be ruled out” 
Non-government agency comment
Many highly respected non-government agencies have also expressed concerns, including:
The Wildlife Trusts:
“The Wildlife Trusts are very conscious of the hardship that bovine TB (bTB) causes in the farming community and the need to find the right mechanisms to control the disease. However, we believe that a badger cull is not the answer. Biosecurity and vaccination should be at the centre of efforts to tackle this disease rather than a badger cull.” 
The Wildfowl and Wetlands Trust:
“WWT ensures that it takes a science-based approach in all its work… WWT is opposed to the proposed culling of badgers as this does not represent a sustainable approach to disease control. More worrying still is the likely futility of this as an effective disease control measure. Based on many years of high quality scientific research, the Independent Scientific Group on Bovine TB concluded to Government in 2007 that ‘badger culling can make no meaningful contribution to cattle TB control in Britain’ and that ‘the rising incidence of disease can be reversed, and geographical spread constrained, by the rigid application of cattle-based control measures alone.’
“The science indicates that culling of badgers is not an effective means of reducing disease due to the complexities of social structures of badgers and how severe disturbances to these structures caused by culling activities exacerbates the disease problem at the periphery of the cull area. Research indicates that over a long period of time a modest reduction (16%) in bovine TB outbreaks might be expected yet this slight ‘benefit’ is outweighed by the economic cost of this long term expensive process.” 
Royal Society for the Protection of Birds (RSPB):
“…we have never been convinced that the best way to help farmers is to force them to foot the bill for a contentious cull that is only expected to reduce outbreaks by about 16 per cent. This is a lot of effort for a small gain. Bovine Tb needs tackling properly and we believe vaccination offers the best hope for cattle, badgers and the industry.” 
Prominent public figures
Prominent conservationists and scientists have also expressed serious concerns about the government’s policy in the media including:
Sir David Attenborough, Naturalist and Broadcaster:
“You may think culling [badgers] is the answer and it sounds easy to start with but it can very well make things much worse… At the moment TB is localised. If you kill all those badgers what happens then? Firstly those survivors will go out and carry the disease to areas that were hitherto unaffected. Other badges slowly colonise and are infected themselves. There is good scientific research available to show culling badgers can make things worse not better.”
Bill Oddie OBE, Naturalist and Broadcaster:
“There is an appalling bloody-minded arrogance about the government’s decision. Opposition to the cull is not based on sentimentality, but on the fact that a great deal of thorough research suggests that it won’t work.”
Mark Carwardine, Zoologist and Broadcaster:
“We’ve had over 40 years of rigorous scientific studies. It’s all been commissioned by the government, it’s paid for by the government. I say ‘paid for by the government’, of course it’s all been paid for by the taxpayer to the tune of at least £49 million and that’s resulted in about 150 scientific papers. And the result of all that study is that we know for sure that killing badgers, culling badgers is not only not going to work it will actively increase the spread of bovine tuberculosis.”
Simon King, Naturalist and Broadcaster:
“… far more likely if a cull were to go ahead is a disturbance of badger populations and as a consequence … the perturbation effect. What does that mean? It means badgers – terrified naturally – running out of their normal homelands, out of their territory and into adjacent territories. Now should one of those badgers, and let’s face it not many of are likely to carry the disease, but should one of those badgers be carrying bTB its going to infect the neighbouring population which might be perfectly healthy. And this has been shown again and again through scientific process.”
Humane Society International/UK concurs with the overwhelming scientific consensus that killing badgers will not solve the problem of cattle TB and could in fact make the situation considerably worse.
2. Jenkins, H.E. and Woodroffe, R. and Donnelly, C.A. and Cox, D.R. and Johnston, W.T. and Bourne, F.J. and Cheeseman, C.L. and Clifton-Hadley, R. and Gettinby, G. (2007) Effects of culling on spatial associations of mycobacterium bovis infections in badgers and cattle. Journal of applied ecology, 44 (5). pp. 897-908. ISSN 0021-8901
3. Jenkins HE, Woodroffe R, Donnelly CA (2010) The Duration of the Effects of Repeated Widespread Badger Culling on Cattle Tuberculosis Following the Cessation of Culling. PLoS ONE 5(2): e9090. doi:10.1371/journal.pone.0009090
5. Licensing the control of badgers (Meles meles) to prevent the spread of bovine tuberculosis in cattle: Advice provided under the Protection of Badgers Act 1992 and Wildlife & Countryside Act 1981 (as amended). Natural England, December 2010
6. Bern Convention.
8. The impact of culling on badger (Meles meles) populations in England and measures to prevent their ‘local disappearance’ from culled areas – Supplementary advice provided under the Protection of Badgers Act 1992 and Wildlife & Countryside Act 1981 (as amended). Natural England, July 2011