Campaigners against a planned badger cull have received mixed news after environment secretary Owen Paterson confirmed the cull would be delayed until summer 2013.

Paterson said the government was "absolutely committed" and that there would be no change to government policy. He said: "I am utterly convinced badger control is the right thing to do."

Paterson explained that he had received a letter from the National Farmers Union, in which they explained the cull could not go ahead as planned.

They said badger numbers were significantly higher than had been estimated and farmers were not confident they could remove the number of badgers needed for the cull to be effective.

Paterson said the process should have started this summer but had "moved beyond the optimum time for an effective cull".

Research suggests that a badger cull would be ineffective in reducing bovine TB in cattle unless at least 70 percent of the badgers were killed.

The government was planning to pilot the cull in West Somerset and West Gloucestershire in the belief that a large reduction of badger numbers would reduce the spread of bovine TB in cattle.

10-year study

Its arguments, however, were at odds with a 10-year study into badger culling by the Independent Scientific Group that said the process had little or no effect on the spread of the disease.

"Badger culling can make no meaningful contribution to cattle TB control in Britain. Some policies under consideration are likely to make matters worse rather than better," the report concluded.

Plans for the cull will be discussed in the House of Commons on 25 October. A mass lobby against it is planned for parliament.

The RSPCA welcomed Paterson's announcement that the cull would be delayed but wanted it cancelled.

Chief executive Gavin Grant said: "This is good news for badgers, cows, dairy farmers and animal lovers alike. Hopefully it marks the beginning of the end for these unscientific, foolish and cruel plans to cull badgers.

"We welcome this postponement, but this must not be a temporary reprieve, but must mark an end to all cull plans.

"Science, the public and MPs from all parties had said very clearly that a cull is no answer to bovine TB.

"The RSPCA stands ready to play a full part working with farmers, land owners, government and conservationists to move forward rapidly and constructively to tackle this dire disease in cattle and wildlife."

Writing for the Guardian, Brian May, who launched the petition to stop the cull, said: "What we need is a complete abandonment of this plan to cull badgers, which has always been irrelevant.

"I firmly believe that in a year's time, plans for vaccination of cows will be so advanced that it will be clearly nonsense to consider going back to this policy of culling, which has no firm basis in science whatsoever. And it was in danger of alienating the farming community from the public.

"I have firm hopes we will move from postponement to cancellation."