"It will stand out like a lighthouse in this darkness of COVID," said Britain's double World Cross Country Championships silver medallist, who now works worldwide as a commentator on athletics meetings and road races. 

"It's an amazing opportunity that they have grasped really well."

Since the coronavirus pandemic took hold, the Virgin Money London Marathon – which will hold an elite race and a virtual race involving a world record number of 45,000 entrants contemporaneously – is the only World Marathon Majors race that has been able to go ahead following the reluctant decisions taken by Boston, Berlin, New York City and Chicago to call off their 2020 runnings.

The circumstances have also confounded large-scale marathons outside the World Marathon Majors set-up, such as Amsterdam and Paris.

A spokeswoman for the Paris Marathon, due to have taken place in mid-November, told insidethegames: "This year is so weird…we learn to work differently with this pandemic. 

"We are very sad with all the cancellations. We have tried to maintain the event but feel obliged to cancel the 2020 edition. Our priority remains the health of everyone."

What seems clear is that each marathon has its own culture and its own economic model.

A spokesman for the New York City marathon told insidethegames: "Our top priority is always the health and safety of everyone involved in our events.

"We work in close partnership with Government officials on all event decisions and considered a variety of factors in determining whether we could host the marathon with only an elite field, including our organisation's history of having elites run with the masses, the ongoing uncertainty around the spread of the pandemic and a number of other factors from financial challenges to travel restrictions.

"Ultimately, we determined that hosting an elite-only race wasn't a feasible option for us."

David Monti, who spent 19 years recruiting and managing athletes on behalf of New York Road Runners before stepping away in January this year from his connection with the New York City Marathon – he is now concentrating on his work as a journalist publishing Race Results Weekly – told insidethegames: "Speaking as an independent journalist, I will say that in the United States road running is looked upon much more as an activity than a sport. 

"Big race organisers don't see the point in holding small events just for elite athletes as this runs counter to the 'big tent' approach their business models are based upon and their sponsors want. A scaled-down big city marathon just isn't a big city marathon.

"Moreover, there have been very few 'micro races' this year for top athletes in the USA when compared to Europe, although there have been track meetings. In Europe road running is looked upon more as a sport than it is here.

"I am gobsmacked that London was able to sell 45,000 virtual entries. The revenue from those entries meant that the elite race could go on, although the agents tell me the financial compensation for athletes is much lower than usual (totally understandable).

"NYC does have a virtual race, but I don't know how many runners have signed up.

"Finally, state and local regulations make gatherings impossible in many places, even if there is a secure perimeter. New York City has been particularly tough on this – rightly so after so many deaths at the beginning of the crisis."

Hugh Brasher, race director of the London Marathon, readily accepted the suggestion that putting the event on this year represented his biggest challenge since taking on his role from Dave Bedford in May 2012.

Asked why London alone of the World Marathon Majors hosts had managed to put on its elite race – shifted from the original date of April 26 – since the coronavirus pandemic took hold, he told insidethegames: "The circumstances surrounding every single event are very, very different. 

"Courses are different, transportation to the starts is different, the people taking part are different, the spectators are different.

"How the events work from a financial point are very, very different, and also what their goals are."

In staging the elite race, London has taken from the experience of Formula One and Test cricket events earlier this year in creating biosecure "bubbles", both for the event and for the hotel 20 miles outside of central London where the runners, who will begin flying in tomorrow, will be exclusively accommodated amidst 40 acres of grounds.

The elite race will take place over slightly more than 19-and-a-half laps of a flat loop course within St James's Park, close to Buckingham Palace, and finish in the traditional spot on The Mall.

"I don't know about other marathons," Brasher added. "Because I am not running their businesses. In life you need to look at what you can control, and what we have had is amazing support from the Mayor's Office, from Transport for London, from Royal Parks, from the Boroughs. They all want this event to go ahead.

"Because after 40 years it's done so much for fundraising, it's done so much for communities coming together, for London tourism. It is one of the crown jewels of British sport and it has become that in 40 years.

"If you look at other ones, they are 150-years-old – whether it's Wimbledon, the FA Cup final, the Boat Race, the Grand National.

"So through our hard work and the history of the event I think that the love people have for the event have repaid us in the sense that people have allowed us to move the event, allowed us to use St James's Park, have gone out of their way to help us to still put that event on, and to inspire the 45,000 people who will be running the event on the same day from their houses in their own way.

"That is fundamentally what the marathon is all about, which is inspiring activity. That's what we have been intent on trying to make happen."

Looking ahead, the London Marathon organisers switched the 2021 edition from its traditional April slot to October. 

The question of whether another biosecure operation might yet be required even then temporarily discomfited the son of the man who co-founded the London event with John Disley in 1981, the 1956 Olympic 3000 metres steeplechase champion and latterly journalist for The Observer, Chris Brasher.

"Oh blimey," he responded. "I think we are trying to get through this year first. We've been given the permission for the event to move already to October in 2021 through the Mayor's Office and the Parks and the Boroughs to do that, and again it's to inspire activity.

"We are hugely honoured to be allowed to do that. And it makes such a difference – people enter events to have something to aim for, it makes a real difference to your motivation.

"We hope that the world will have come together and found a way through this pandemic by October 2021. We want the 41st race to be the most incredible celebration of a world that is what we have known previously."

Brasher is confident the measures adapted to ensure social distancing and public safety will be fully effective.

"There are protocols for how you run an event in a biosphere environment, and they have already been used in Formula One and cricket," he said. "So we will be using those, and they have been practiced before.

"We are screening off St James's Park, so you won't be able to watch it there. It's live on BBC 2 and BBC 1 so there is absolutely no point in coming to St James's Park as you won't be able to see the race. We are saying to people – watch it on TV and enjoy what we hope will be incredible performances."

No-one could dispute that the personnel required to produce incredible performances has been duly gathered.

The women's race contains the Kenyan who last year at the Chicago Marathon broke Paula Radcliffe's 2003 world record for a mixed race, 2 hours 15min 25sec, by running 2:14:04. 

Next Sunday Brigid Kosgei's target will be the women's-only race world record of 2:17:01 set in London three years ago by her compatriot Mary Keitany, although the presence of runners such as Kenya's current world champion Ruth Chepngetich and 2018 winner Vivian Cheruiyot will ensure it is no time trial.

The men's race will feature Kenya's Olympic champion Eliud Kipchoge, who set the official world record of 2:01.39 at the 2018 Berlin Marathon, and Ethiopia's multiple world and Olympic track champion Kenenisa Bekele, who ran the second fastest official time, 2:01:41, on the same course the following year.

Kipchoge, of course, completed the marathon distance in 1:59:40 on a flat loop course in Vienna last year in an exercise ruled ineligible for record purposes as it was not an open event. He was handed fluids throughout by his support team, he was paced by a laser trail and he was shielded by the rotating formations of dedicated pacemakers.

The Vienna race took place over four-and-a-half laps in Prater Park. Hutchings pointed out that because the runners will be running so many times around the same loop, it could help enormously in the quest for a world record performance.

"The geography of London obviously helps enormously," said Hutchings, who has been a regular press conference interviewer in recent years during the London Marathon build-up week. 

"You have got a dead flat loop that they are going to use in front of Buckingham Palace and around St James's Park. 

"It is easily containable, and while New York has got Central Park maybe the logistics and geography of New York don't lend themselves so well to it.

"It's similar in many respects, while adhering to the rules of marathon running, to the set-up in Vienna. I understand they are going for 60.45 to 61 minutes at halfway. Which would put it well in reach of world record territory.

"In fact one agent I was chatting to a couple of days ago online said he thought the men's world record would go, that Eliud is capable of coming back in something close to 60 minutes. So we may see a little chunk knocked off it."

Such calculations will put additional responsibility on Sir Mo Farah, who has targeted the defence of his 10,000 metres title at the Tokyo 2020 Games and will be pace-making on the day.

"Having so many laps in a limited space enables a much greater depth of information to be fed to the athletes on the circuit," Hutchings added. "They may not have a laser on the road but there will be so much more information that will be fed to them during each lap."

Brasher is also swift to point out the advantage to competing runners of a short loop course.

"As it's over 19-and-a-half laps there are things you can do that make it easier for the athletes," he said. "Effectively you will have a water station at the same point on the course and they are going past it 19 times. So that actually makes it easier for an athlete. They don't normally have the ability to take on fluid that often."

As to how things will turn out on the day – well, that's the eternal question. Brasher believes it may be even more open during this unique edition of the race.

"I think the journey that each elite runner has been on – and we know that Ethiopia has had some difficult times politically in the past few months and that Kenenisa has not always been able to train in the way he would normally – has involved different challenges each will have had to overcome or adapt to.

"I think that is one of the huge unknowns about what will happen on October 4. It really is. You could have a formbook going judged on past races, but I am not sure it will count nearly as much as normally in terms of performance on the day.

"What we have tried to do – we had this amazing field for the 40th race, and we have tried to replicate that as much as possible for the October event, to stick with the athletes that were coming to us and it has been great that they have stayed with us."

The wheelchair races are similarly stacked with talent.  Although last year's London Marathon champion in the men's race, Daniel Romanchuk of the United States, has had to withdraw, the 2019 women's winner, Manuela Schar, will defend her title. 

The men's field includes Britain's own David Weir, the six times Paralympic gold medallist, who won his eighth London title in 2018 and finished fifth last year. Switzerland's double gold medallist from the Rio Paralympics, Marcel Hug, is also involved.

Among Schar's opponents will be home racer Shelly Woods, a Paralympic silver medallist at the London 2012 Games, and Jenna Fesemyer of the United States, making her first appearance in London after setting a personal best of 1:37.02 last year.

The World Athletics decision to open its Tokyo 2020 qualification from September 1 for marathon and race walk events means that British runners who have not yet gained the required times will have an additional target on the day.

The men's entry standard for the Tokyo 2020 Games is 2:11:30, and the target time for women is 2:29:30.

Brasher acknowledges the unique benefits to the annual race of London's unique topography.

"When my father wrote his article in The Observer, he said that London had the course, but did it have the heart and soul to welcome the world?

"So he and John Disley knew at that stage that the course was there, and the green spaces from the start in Greenwich, following the river, and into St James's Park. It is absolutely incredible that a city as busy and as vibrant as London has that green space, and we are incredibly lucky in that."

So did Brasher think his dad, who died in 2003, would have been proud of him for ensuring the 40th London Marathon went ahead despite all the odds?

"I think he would be incredibly proud of the whole team, as simple as that," he said. "We have an amazing team of close to 80 staff who throughout the last six months have gone through so many different scenarios to keep the event alive, to inspire activity.

"And of course there are so many volunteers and boroughs that get involved. So many people make the event what it is. To have communities coming together and to see the world's greatest athletes coming together will be one of the strengths of London.

"We have eight hours of live TV coverage on the BBC. We've had that partnership since 1981, and through it we have changed running and changed sport.

"The number of people that through the pandemic have now started to run, realising that exercise is so good for your physical health, your mental health and that should you get COVID-19 – one of the worst outcomes is for those with obesity.

"The more you can go back to looking at what you can control, if you can control it, exercise can play a major part in that. The more the event can happen, can inspire activity in that way – both through the greatest athletes and the everyday athletes that will be going out to do the run in 23 hours 59 minutes and 59 seconds.

"We will see runners all over the country. And I really hope people will give money to the charities who are so severely affected by the results of this pandemic and need our funds more than ever."