Walkers’ decision to add meat to its previously vegetarian bacon and chicken crisps has outraged vegetarians - and left rivals rubbing their hands with glee.

Golden Wonder said it had seen a sharp rise in interest and visitors to its Facebook page since Walkers revealed last month that it had added chicken to its roast chicken crisps and pork to its smoky bacon flavour in a drive to used British ingredients.

The recipe change has prompted headlines in the national press and comments on Walkers’ Facebook page such as “Vegetarians are horrified you are restricting their choice”, and “Are you mad, Walkers?”

Tayto-owned Golden Wonder was quick to take advantage of Walkers’ move - placing a “vegetarians welcome” banner across its Facebook page and coining the slogan “no animals were harmed in the making of these crisps”.

Mars backtracked on rennet in 2007 - will Walkers?

In May 2007, The Grocer revealed Mars had changed the recipe of its top chocolate brands to include whey containing animal rennet.

The move meant that well-loved brands such as Mars, Bounty, Snickers, Twix and Milky Way bars, as well as Maltesers and Minstrels, were suddenly strictly off-limits to vegetarians.

The recipe change sparked fury among vegetarians. Mars was bombarded with more than 6,000 calls and emails from angry consumers and more than 40 MPs signed a petition in protest.

Just two weeks later, Mars backtracked on its decision, and in full-page ads in the national press, Mars UK MD Fiona Dawson apologised. “We have received lots of feedback that this decision has made it difficult for some of you to continue to enjoy our products,” she wrote. “We made a mistake, we apologise.”

“People were already rediscovering the Golden Wonder brand - and this will be helping,” said Tayto group marketing director Scott Guthrie.

The Vegetarian Society, which was alerted to the recipe change by Walkers owner PepsiCo, described the move as a “backwards step” for the brand.

“Many veggies will be switching to brands that not only value their custom but can produce a snack that doesn’t involve killing animals,” said a spokesman.

PepsiCo, owner of the £478m crisp brand [Nielsen 52 w/e 13 October 2013], announced in January that Walkers would be using British ingredients such as tomatoes from the Vale of Evesham, Cheddar from Somerset, and sour cream from Dorset. It has since revealed it will also use free-range chicken from Devon and Freedom Foods pork from Norfolk. The move will be pushed in its “biggest-ever” ad campaign from 8 March, fronted by Gary Lineker.

Using British Freedom Food and free-range meat gave its crisps “the best, most natural flavour” said Walkers senior marketing manager Marianne McGoldrick, who added that products containing meat would be clearly labelled.