Princess Anne has prompted more anger from animal welfare campaigners by calling for an end to a ban on gassing badgers.

The princess royal waded into the controversy over the badger cull by claiming that gassing the animals was the most humane way of tackling the rise of tuberculosis in cattle.

She made the remarks to the BBC's Countryfile programme to be broadcast on Sunday. In the interview Princess Anne also repeated a much-criticised call she made last year for horses to be farmed for their meat, according to the Radio Times.

Her latest comments were dismissed by experts as ill-informed and were rounded on by the animal rights lobby.

The royal intervention came a day after the environment secretary, Owen Paterson, abandoned plans to extend badger culls across England after an independent report found that pilot shoots were ineffective and inhumane.

A leading badger expert dismissed Princess Anne's suggestion as no better than the shooting cull. Dr Rosie Woodroffe, who conducted a 10-year trial of badger culls, said gassing badgers failed to control the spread of TB when it was tried in the 1970s.

She said: "Gassing badgers was government policy in the 70s and if you go back to reports of the time, there was frustration about how it just wasn't very effective. Sets would be gassed and then opened up again by badgers again and again."

Speaking to BBC Radio 4's Today programme, she said the practice of gassing badgers with cyanide proved to be so inhumane that it was banned in 1982. Woodroffe said: "The problem seemed to be that badger sets are built to hold warm air in and keep cold draft out, so it was very difficult to achieve a lethal concentration of gas. And sub-lethal concentrations of gas were inhumane – that's why ministers banned gassing in 1982."

She suggested the princess was being too simplistic. "It is tempting to think it would be easier to kill badgers when they are a sitting target underground, but it turns out from reports from the 70s that it is just not that straightforward," Woodroffe said.

"There are rumours of farmers trying to use carbon monoxide on the quiet, using a tractor exhaust. That is something that is potentially not very effective and potentially inhumane."

Woodroffe recommended testing the idea of a mass vaccination programme for badgers. She said: "It is not necessarily [expensive] … there are hundreds of wildlife lovers willing to do it for free. It is cheaper than culling because it doesn't require any policing, and people will come forward offering to help to do it. We don't know how effective it could be in controlling cattle TB. It is very promising. What we need are trials of vaccination instead."

Mark Jones, veterinarian and executive director of the animal protection campaign the Humane Society International UK, said: "It is extremely disappointing that a prominent member of the royal family should endorse the gassing of a supposedly protected indigenous wild mammal. Gassing experiments carried out at Porton Down in the early 1980s were abandoned because of the appalling levels of suffering to which the badgers were exposed.

"Any attempt to reintroduce gassing would doubtless result in a slow and painful death for many badgers, and potentially other non-target animals."

He said the princess should be better informed before making public statements on such controversial and divisive issues, and questioned her views on horsemeat.

"Princess Anne's passion for horse riding is not in doubt, but she's simply wrong when it comes to horsemeat, and as a vet I would urge her to think again. Horse neglect and abandonment continue to be an issue throughout Europe and in countries exporting horsemeat to the EU, even though sending a horse to slaughter is already an option."

Peta, or People for the Ethical Treatment of Animals, offered to send the princess on one of its eight-hour courses on empathy and animal protection.

It's managing director, Ingrid Newkirk, said: "Peta's course teaches the golden rule: treat others as you wish to be treated. Those who have everything in life should not be calling for the death of horses and badgers, whose only crime is to be born into a world where humans are in charge and other animals are viewed by some as replaceable."