The government is to review the controversial badger cull as part of an inquiry into its strategy to clamp down on bovine TB.

The review raises the possibility that experts conducting it will examine disputed evidence about the cull’s efficacy, potentially paving the way for a change in policy.

When the review was announced last month, its terms of reference said it would “not revisit the rationale for current interventions in the strategy. It will take a prospective and not a retrospective view. It is not a review of badger culling.”

Rosie Woodroffe, a senior research fellow at the Zoological Society of London, Institute of Zoology, told the Vet Times that the review was “disappointing because its scope excludes badger culling, which is the most controversial and least evidence-led part of the strategy”. The number of badgers culled has risen from 615 animals in 2014 to 19,274 in 2017 as the scheme has been extended. But the number of cows that succumbed to tuberculosis rose from 27,474 to 42,000 as the disease has spread.

Launching the review, farming minister George Eustice said early analysis of the first two cull zones suggested that it was reducing the incidence of the disease, a claim disputed by conservationists.

Now a spokesman for the Department for Environment, Food and Rural Affairs (Defra) has explicitly confirmed that the badger cull will form part of the review, leading to claims that the government has quietly orchestrated a U-turn. This was denied by the spokesman, who told the Observer: “We have always made clear that this review will consider all areas of our existing bovine TB strategy, including culling.”

The badger campaigner, Tom Langton, said the decision to omit the cull from the original scope of the review was proof that Defra had been “running scared of the vet and cattle industry” who believe it is vital for the disease to be eradicated. He called for the terms of reference to be changed so that the review would take both a retrospective and prospective view.

“How will the review panel know what to do?” Langton asked. “Is it being asked to ignore crucial aspects of cattle measures and badger killing by ignoring what has gone wrong over the last five years? Is this an attempt to fudge the issue so that the review has no clear remit?”