Tana Ramsay seemed unmoved, even nonchalant, in the aftermath of revelations about her husband Gordon's alleged infidelity. Hours after it was claimed "professional mistress" Sarah Symonds met the celebrity chef for a tryst at a London hotel, taking with her three phials of a sex stimulant, Mrs Ramsay posed smiling for photographers with her arm around her allegedly wayward husband.

The Ramsays looked every inch the perfect couple, as they were perceived when they were voted Celebrity Family of the Year in 2007. Seeing them hugging each other outside their Georgian house on Wandsworth Common after Sunday's torrid claims, many might have wondered whether any mistress, real or imagined, could make an impact on this apparently happy pair. But whatever united front the couple put on, the allegations will have had an impact on their relationship. As ever they will be depending on one person to hold everything together - the marriage, the business empire and the public image.

If anyone can stitch it all back together, it is his father-in-law Chris Hutcheson.. He is also the one person who can steer the Ramsay empire to greater success. He has a steely grip on the business and is known as the Grim Reaper for his ruthlessness. On Sunday, during a five-hour family council of war, Hutcheson would have played a key role.

The bond between Ramsay, 41, and Hutcheson, 60, is something of a phenomenon. When Ramsay met Hutcheson, he was a talented young chef but clueless about business. Hutcheson, who had made a fortune, said he would help guide Ramsay's career "as a hobby". Now they straddle a £100 million empire yet there is far more to their relationship than mere business. Ramsay, who rejected his own father, adores Hutcheson. He talks to him at least 15 times a day on a retro-style telephone that Hutcheson uses as a hotline at the offices in Victoria that are the headquarters of the Ramsay global corporation. Ramsay credits Hutcheson with helping him to fabulous success. They work together, run marathons together and swap dreams of even greater riches.

Hutcheson, silver-haired and always impeccably dressed, is the godfather of the Gordon Ramsay brand. He has helped guide Ramsay from his days as an up-and-coming chef to his current pre-eminence. His beloved daughter Tana ,33, born Cayetana, has been with them every step of the way and together they make a formidable triarchy.

The beginning was not promising. In the early 1990s, Ramsay was the chef at Aubergine, an Italian-owned restaurant in Chelsea. The former footballer and rough-edged Scotsman had just come back from Paris where he had begun to refine the delicate cooking style that was to become his trademark, before it gave way to his famously coarse verbal delivery. Aubergine had been struggling but with Ramsay in the kitchen it acquired cachet and a new clientele, among them restaurant professionals who wanted to see whether Ramsay's cooking was as good as the gossip claimed.

In 1993, when he was 27, a fellow chef who was dating Tana took her to Aubergine with her parents, Chris and Greta. Ramsay joined their table and chatted. Whatever Tana thought of him, he left her father unimpressed. As Ramsay recalled in his book Playing With Fire "I learned later that Chris, Tana's dad, had said to his wife Greta that I was totally preoccupied with myself and right up my own arse. Greta apparently smiled sweetly and said that I reminded her of Chris at that age."

Ramsay and Tana married in 1996 and have four children. She has written extensively on food and has her own cable TV programme, The Market Kitchen. As Ramsay's celebrity grew it was inevitable that he would become the target of rumour. His attractiveness to women meant he was often under near-attack from some and journalists have been exchanging stories for years about those who have fallen at his feet.

The claims on Sunday suggested Ms Symonds has been his mistress for seven years. This is puzzling because during that time Ramsay has hardly made a move without his father-in-law knowing about it.

Ramsay is the first to define the closeness of their working and personal relationship. "We are," he says, "as alike as two wings on a plane."

That unlikely craft began to soar when they formed Gordon Ramsay Holdings, in which Hutcheson has a 31 per cent stake. After Aubergine, Ramsay had been tempted to take over as head chef at a new, upmarket London restaurant. Hutcheson persuaded him he would do far better as boss of his own outfit. This led to the opening of Ramsay's first restaurant in Royal Hospital Road, Chelsea, where he was to gain three Michelin stars.

Then Hutcheson helped negotiate deals that led to the acclaimed Petrus and Gordon Ramsay at Claridge's, which quickly started to turn over £2 million a year. In 2005 the Inland Revenue's Special Compliance Office put Ramsay's personal tax returns from 2001 to 2004 under intense scrutiny. It took more than two years before the revenue was satisfied. Ramsay was "more than happy to leave this to Chris to deal with while I got on with my real life".

He also let Hutcheson do the firing. Hutcheson has a lively temper (Ramsay: "I always grit my teeth when Chris starts to turn puce") and he can leave staff quaking.

Witness this episode. When Neil Ferguson, an old Ramsay hand, was appointed head chef at his flagship restaurant in New York, Gordon Ramsay at The London, returns were disappointing.

Overheads, including overtime for staff, kept profits down. Hutcheson flew to New York to sort things out. Hutcheson's Grim Reaper nickname came about because when he appears in a restaurant staff wonder who is about to get the chop. At The London it was Ferguson. He recalled: "Chris came in and said 'I need you to go home to your wife, tell her and then come back and pick up your stuff.' My wife was so upset, she just cried and cried. Neither of us expected it. I had no idea it was coming. I wasn't given a reason. Gordon never alluded to any problems - it just happened out of the blue."

Ramsay later said Ferguson was "too nice a man to get brutal when necessary." That description, apparently, did not apply to his father-in-law.

Then Ramsay's television career began pulling in more money than the restaurants. In America, Fox wanted him to film Hell's Kitchen and Kitchen Nightmares in 55 days without a break. Fox were already paying around £1 million a series for each programme but Hutcheson argued that the burden of the new schedule was worth more. The TV company offered an extra $250,000 without demur. Little wonder Ramsay says his first "real break" was meeting Hutcheson.

Together they have built a remarkable brand. When Gordon Ramsay Holdings filed its latest accounts recently - rather late and just ahead of action by the fiscal authorities - it showed Ramsay was the world's highest-paid chef with an income of £15 million.

He earns £1 million from each book he produces and he is contracted to do two a year. His Channel 4 contract is worth £2 million a year and his earnings in America alone are worth around £8 million. With more than 20 restaurants around the world and endorsement deals, including one for Gordon's gin, Hutcheson predicts that the Ramsay empire is set to produce £100 million revenue by 2010.

But what if the Ramsay bubble bursts? With the economic outlook darkening by the day, even he is unlikely to be immune. According to a former business associate of Hutcheson, he knows only too well how recession can damage even a successful company. Hutcheson had a screen printing business in East London which suffered in the recession of the early 1990s. "Chris was hurt hard," the associate told the Standard. "He lost a lot of money".

Hutcheson expresses confidence now and says the first £100 million is the hardest to earn: "It's the hundreds of millions that come after that that will be more interesting," he said.

But even he admits Ramsay is spreading himself thin and danger signals have already appeared. Earlier this year Ramsay lost two Michelin-starred Petrus in Mayfair when his number two, Marcus Wareing, took it over. He was replaced at the Connaught by French chef Helen Darroze and his Foxtrot Oscar restaurant in Chelsea is to be closed two days a week because of falling demand. A snap check at six Gordon Ramsay restaurants in London revealed that tables can be booked days in advance, rather than weeks as was usually the case. In Dublin, chef Paul Carroll left the Ramsay operation, Powerscourt, taking most of the staff. He said they rarely saw Ramsay.

Ramsay's friend Michael Winner has drawn attention to the fact that it is hard to find a meal actually cooked by the chef himself. He said: "If I buy a Canaletto, I expect it to have been painted by him and not his students."

Ramsay admits he occasionally loses sleep over the thought "it will all go tits up". Certainly these are testing times. And Ramsay may find he now needs his father-in-law more than ever.

• 

  Supersize superport: London Gateway

  London Gateway, the £1.5bn container port under construction on the Thames at Thurrock, will have capacity to unload six of the world's largest ships at one time and have as much impact on the capital as a new airport or half a dozen Westfield shopping centres

  ---

• 

  One stylish affair: Matthew Williamson

  With London Fashion Week kicking off on Friday, British designer Matthew Williamson tells Rosamund Urwin about breaking up with his ex, post-show partying and his new model man

  ---