NOT since Ealing comedy Passport to Pimlico has such a modest little settlement made such an audacious bid for global recognition. Dunblane has long been a location of special interest on the sporting map, particularly since it acquired a golden post box, but its quest for world domination continues this weekend. With a little help from selected friends, this population of 8,000 people hopes to beat Belgium to effectively become the best tennis-playing nation on the planet.

Great Britain's best hopes of securing their first Davis Cup title since 1936 rest squarely on the shoulders of the Murray clan, and by that I also include the man Judy Murray says has become almost like a surrogate third son. The tennis-playing equivalent of the fifth Beatle, Davis Cup captain Leon Smith, has named a fab four of Andy and Jamie Murray, Kyle Edmund and doubles specialist Dom Inglot for the tie against the Belgians, although James Ward could also feature.

The matriarch of Scottish, British and Stirling and Clackmannanshire tennis surveys what she has created and is proud, but knows the deal isn't sealed just yet. She has seen enough in her role as Britain's Fed Cup captain to be well aware that underdogs often bare their teeth on Davis Cup duty. Not only do the Belgians boast a dangerous star player in the form of David Goffin, they have a decent supporting cast including Steve Darcis (85), Ruben Bemelmans (105) and highly-rated youngster Kimmer Coppejans (131). They get to choose Andy's least favourite surface, particularly days after playing a high profile tournament on a hard court, clay, and a hostile crowd in the 13,000-capacity Flanders Expo Centre in Ghent will further hope to level the playing field in the Belgians' favour.

Perhaps Judy Murray would be more concerned about this if she didn't know from experience that her youngest son usually finds such courtside conditions more inspiring than anything. "People get fired up and produce extraordinary performances against the odds when they play for their country," said Judy, in an exclusive interview with Herald Sport. "When it comes to nations trying to get into the head of the opposition, Italy and Argentina are probably the toughest places of all to play Davis Cup in. But I think Andy is one of those characters who finds something special when he is up against the wall. It almost like if you tell him he can't do something, he will do everything to prove that he can.

"I remember watching him play a match many, many years ago in Miami, against Paul-Henri Mathieu. He was quite young, maybe about 19 or 20. He was 6-2, 5-3 down in difficult, windy conditions and he wasn't playing great. Somebody stood up in the crowd and screamed at him: 'You've got nothing, Murray, nothing!'. Andy stood on the court and absolutely stared the spectator down. He won 2-6, 7-5, 6-2, hardly lost another game. But if that guy hadn't stood up, he would have probably gone out. That is the real kind of warrior mentality he has got - if he wants to prove a point."

So consistently have her progeny produced on the big stage that it must be hard to keep up, but without a doubt there would be something special about the extended family delivering in these circumstances. It takes a lot, after all, for a Davis Cup win to come together. Britain has waited 79 years since their last one and could easily do the same again.

"It would be a huge thing," Judy said. "Jamie has obviously played in Davis Cup over many years, but he didn't always have his place in the team because Britain has a lot of good doubles players. But over the last 18 months he has just gradually been getting better and better at what he does and it is great to see him playing World Tour Finals and winning rubbers in quarter finals and semi finals of Davis Cup."

Andy also has a patchwork association with this trophy. A feature in the team since a 2005 tie with Israel, the younger Murray sibling felt unfairly singled out by former Davis Cup captain John Lloyd back in 2010 when he withdrew from against Lithuania, but his commitment since returning to the fold under Smith has been total. "If you make it to semi finals or finals of a slam you are exhausted," says Judy. "But this year I know it was a huge goal for Andy to play Davis Cup and he has made himself available for all of the ties even when his body and mind were very tired, especially after Australia and Wimbledon."

Then there is her surrogate third son, who cut his teeth as a coach under Judy, working with Andy. There are still hopes of persuading him to double up with a badly-needed overseeing role in coaching north of the border but this Davis Cup bid has understandably swallowed up a lot of his time, as has travelling with the currently coach-less Edmund.

"Leon came to me when he was 21," she added. "He had just dropped out of college and he wanted to be a tennis coach. I was Scottish national coach at the time, Andy and Jamie were 11 and 12, and he asked me if he could come and work with me. I took him on as an apprentice, so he in effect is like my third son. He is. I say that to people. For me to watch him develop not just as a coach but as a young man is a huge thing for me as well.

"Back then, he had the bleached blond hair, the curtains-style haircut which David Beckham used to have and a diamond in each year. He was Beckham-esque. For the little boys in the squad - Jamie, Andy, Jamie Baker, Colin Fleming - they all thought he was the coolest thing ever. When I watched the three of them walking out to a packed crowd in Glasgow for the semi final I couldn't believe what I am seeing here."

It may be the biggest tie in Scottish and British history but typically this country's first lady of tennis, who will become a grandparent when Andy's wife Kim has a child in February, has more on her mind than that. It is also another glaring opportunity to sell the sport to a generation of kids who are inspired by the successes of her children only to find that the infrastructure to keep them in the sport seems insufficient. There is no doubt the appetite is there, judging from the response she receives from young children on her numerous Tennis on the Road visits, and young girls on her LTA-sponsored MissHits programme.

Another date in the diary is December 8 when she will discover whether her plan for a tennis academy with attached Murray Museum on greenbelt land at Park of Keir between Dunblane and Bridge of Allan will be approved by planners, but will reluctantly forget about it if she is rebuffed for a second time. Instead of life on the road, that development would provide Murray with a badly-needed base to work from. Who knows, it might even be the foundation for a second generation of the town's global dominance.

As an Ambassador for Head Tennis racquets in the UK, Judy Murray is launching the new Head Graphene XT Radical racquet series and this accompanying video https://www.youtube.com/watch?v=RWhyQumlbrM