The Hampstead Hill School pupil who won a competition to open the controversial McDonald’s restaurant in Hampstead High Street in 1993 has now revealed he wishes he’d “never agreed to take part” – and has gone on to work for an animal rights group that is one of the company’s staunchest critics.

Ben Williamson, now aged 28 and working for the organisation People for the Ethical Treatment of Animals (PETA), became the first person to eat at the fast-food branch after it opened following a 12 year opposition campaign by Hampstead residents and shopkeepers.

He now describes the occasion - in which he bought a typically Hampstead Filet-O-Fish - as a “schoolboy PR stunt” and said he was “thankful” the restaurant was now closing.

“Had I known when I was seven what I do now about how animals on factory farms are deprived of everything that is natural and important to them I never would have agreed to take part.

“Thankfully, times are changing and more and more people, like me, are switching to a healthy and compassionate vegan diet.

“Hampstead’s McDonald’s may be the latest casualty, but given how quickly the market for meat-free meals is growing, it certainly won’t be the last.”

At the time, the new McDonald’s branch in Hampstead High Street opened to champagne on ice and queues out of the door despite causing one of the most protracted and heated planning rows in the history of Camden.

But after 20 years serving Big Macs and Happy Meals the company announced earlier this month it would be closing its doors to Hampstead residents on Sunday (November 17).

In a statement the company said it was “sad to leave Hampstead after so many years of successful trading”, adding: “We decided this was the right opportunity as we received a good commercial offer to purchase the remainder of our lease, which is set to expire in 2016.”

Le Pain Quotidien, which already has a store in South End Road, is to replace the burger chain.