Abstract – owned by businessman Barry Larsen and run by French chef Loic Lefebvre – won a string of awards despite being criticised by the outspoken star.

But now Mr Loic Lefebvre and his partner Caroline Cordeir, who was general manager, have walked out on the Castle Terrace restaurant in the city's West End after a row with Mr Larsen.

Mr Larsen insisted the pair had decided to return to France for "very personal reasons".

But Ms Cordier said in an e-mail they were leaving "with regrets" after falling out with the businessman.

The pair moved to Edinburgh from Inverness – where they had worked in the original Abstract for three years. They were given a grilling by Ramsay when they featured on Kitchen Nightmares.

He ridiculed the over-complicated food in a series of explosive exchanges, and labelled Mr Lefebvre "stubborn, pretentious and arrogant".

But, after adopting some of his suggestions, the restaurant went on to be named a "rising star" in this year's prestigious Michelin guide.

Their Edinburgh venture followed the same formula that had been successful in the Highlands, combining local produce with French cooking.

Mr Larsen said: "They are leaving for very personal reasons. Caroline didn't like Scotland.

"She was very unhappy here. She said she found the people very cold and unfriendly.

"She spoke to me on Saturday and we just agreed she would go. Loic was very disappointed. He didn't want to go, but he had to support his partner and she wanted to go back to France."

Ms Cordier said there had been a financial disagreement. But Mr Larsen said this was "completely untrue".

He said: "As long as Loic was employed with the company, he was entitled to a 25 per cent share of any profits. This agreement was purely between me and him. As he has now left, it is terminated."

Ms Cordier wrote she and Mr Lefebvre had left with "huge regrets but for good".

She added: "Abstract now is left with no manager, no head chef, just a team of young people not strong enough to steer this big ship.

"Abstract was a great big ambitious and exciting project for Loic and myself, located in the middle of a fantastic and so welcoming city."

She said she wanted to thank guests and reviewers, and regretted not taking the venture any further.

Mr Larsen said the restaurant would be carrying on as normal. A new head chef, Damian Rollan, and general manager Alex Foch have already been appointed.

Both have been with the restaurant since it opened in March. He said: "Our team is very strong. In a business like this, it's never about two people.

"There's no effect on the quality. We've had many customers every day this week, and they've all enjoyed their meals."