Christmas is coming and the goose is getting fat. But animal rights campaigners are asking shoppers not to put a penny in the foie gras industry's hat this year.

The appeal came as farmers producing the traditional French delicacy issued an astonishing mea culpa over the way the fatty goose and duck liver is produced.

It also followed the decision by two high-profile chefs either side of the Channel – Gordon Ramsay in the UK and Joël Robuchon in France – to drop their foie gras supplier after the publication of shocking photographs showing the extent of suffering endured by the birds.

Cifog, the body representing French foie gras producers, has admitted that farmers may have "gone a little too far".

Spokeswoman Marie Pierre Pe said producers were determined to be more open and transparent about the most controversial aspect of foie gras production, the gavage, or force-feeding, of ducks and geese. This is most often done by pushing a tube down the bird's throat and pumping a grain mix into the stomach.

"Of course gavage is not very romantic and so we avoided talking about it. But now we are trying to explain it more and more," Pe said. "In the 1980s about 30% to 35% of foie gras was coming from eastern Europe and we had to improve production to be more competitive, but perhaps we've gone too far," she added.

Sébastien Arsac of the L214 Ethics and Animals association, which runs a Stop Gavage campaign, said most French foie gras production is now industrial not traditional. France produces and consumes 75% of the world's foie gras.

"We would like chefs to come up with a new French gastronomy not based on the suffering and ill-treatment of animals," Arsac said. "It's hard to change attitudes because people see foie gras as something French and traditional, but we are seeing a slow change and people are moving away from this."

L214, which derives its name from a law in the French rural code, says a survey it commissioned in 2009 showed 18% of French consumers said they would refuse to buy foie gras on the grounds of animal cruelty. This has now risen to 29%, it said.

An 89-page scientific study, adopted in 1998 by the European commission, found death rates among force-fed birds was up to 20 times higher than usual. The report described foie gras as the "pathological liver of a bird suffering from hepatic steatosis" – a buildup of fat cells that, in humans, would usually be caused by alcohol abuse or obesity.

Producers say the rural code decrees: "Foie gras is part of the protected cultural and gastronomic heritage of France."

Xavier Fernandez ,of the institute of agronomic research in Toulouse, said: "Force-feeding is no more shocking than any other method of animal husbandry. At the end of the day, the real question is whether we should be rearing animals for human consumption at all."

Arsac said animal rights campaigners were planning a busy seasonal period. "Producers are spending millions on TV advertising in the runup to Christmas and the new year. We have to counteract that by reminding people that foie gras is produced by making animals suffer."