London Marathon 2020: The rivals, the virtual runners, coverage details and more

London Marathon organisers are facing unique challenges posed by the coronavirus pandemic

The Cutty Sark, Tower Bridge, Big Ben, thousands of charity runners and even more people cheering them on from the pavements.

This year's London Marathon won't have any of them.

Instead, the only sign of the race happening in the capital on Sunday will be a barricade of screens, snaking around St James's Park.

Behind them, away from any spectators, the world's best marathon runners will compete over 19 laps of a specially designed looped course.

On the same day, 45,000 other people, unable to run in the usual mass participation event because of coronavirus restrictions, will cover 26.2 miles from wherever they are in the world, raising vital money for charities.

• Virtual runners tackle challenge around the world

• Race can bring 'hope to the world'

• We want your virtual London Marathon stories

"Start, finish, feel it and enjoy it," said Kenya's Eliud Kipchoge, four-time winner and world record holder, when asked for his advice for those running remotely.

"In spirit we will be running together."

This is all you need to know about a marathon like no other.

A race on screen and behind screens

Workers assemble screens to keep spectators from viewing the race

The Berlin marathon was supposed to take place last weekend. Chicago was to be next weekend. New York would have been in four weeks. All have been cancelled as the world attempts to rein in coronavirus.

London could easily have gone the same way. However, after rescheduling from its usual April date, the race is going ahead in very different form.

While the finish will be in the usual place on The Mall, the elite runners will be racing on a 1.3-mile course, with an additional 1,345m to cover after 19 laps.

The athletes, who have been staying in a biosecure hotel since arriving in London, will be able to monitor their pace more easily than usual.

At the end of each lap, screens will relay individual predicted finish times.

However, hopes that Kipchoge and compatriot Brigid Kosgei might improve on their world records are likely to be scuppered by damp weather and the five corners they encounter on each lap.

The worst of the weather is due in the early morning with the women's field forecast to encounter heavy rain and temperatures of about 10C when they begin at 07:15 BST. The men's race follows at 10:15 BST, with a mixed wheelchair race under way just after 13:10 BST.

• London Marathon 2020: Follow live coverage across the BBC

• Five stories of virtual runners

• Quiz: How much do you know about the history of the London Marathon?

Kipchoge v Bekele off

Bekele (left) and Kipchoge were the centre of attention at Wednesday before Bekele's withdrawal

The 40th London Marathon was going to include one of the most keenly anticipated head-to-heads in the distance's history.

However, Ethiopia's Kenenisa Bekele, who came within two seconds of Kipchoge's world record of two hours one minute and 39 seconds in Berlin last year, pulled out of the race on Friday with a calf injury.

Bekele's withdrawal leaves compatriot Mosinet Geremew, who finished second to Kipchoge in London last year, as the man most likely to upset the Kenyan.

Defending champion Kosgei, racing for the first time since breaking Briton Paula Radcliffe's world record in Chicago last year, takes on world champion Ruth Chepngetich and 2018 London champion Vivian Cheruiyot.

American Daniel Romanchuk is not in London to defend his wheelchair title, which may leave the way open for 41-year-old Londoner David Weir to claim a record-extending ninth win in the event.

Weir's compatriot Shelly Woods, a two-time champion, is racing at London for the first time in four years since the birth of her son. However, Switzerland's Manuela Schar will be hot favourite, having won the past nine major marathons she has entered.

• WATCH: Eliud Kipchoge - My sub two-hour marathon on BBC Two, Saturday, 13:00 BST

There will be another big name on the startline, but one who won't make it to the finish. Mo Farah, who has switched back to the track since finishing fifth in 2019, will be a pacemaker.

Degitu Azimeraw, last year's Amsterdam Marathon champion, and coach Haji Adillo Roba won't be attending. Both tested positive for Covid-19 in their native Ethiopia as part of the organisers' pre-race screening programme.

Athletes and their coaches were tested again on arrival in the United Kingdom and have been wearing special devices that warn them when they are too close to other people.

Shoe technology debate continues

The Nike shoes worn by Kipchoge in his sub two-hour marathon time trial event in Austria last year have fallen foul of the new World Athletics regulations

It won't just be famous faces to keep an eye on. It is worth watching the feet as well.

Kipchoge, Kosgei and a host of the frontrunners will wear shoes incorporating Nike's controversial technology. The shoes, which combine large amounts of highly resilient foam cushioning and an angled carbon plate, have coincided with a dramatic drop in marathon times.

The five fastest of all time, along with Kosgei's world record, have all come since September 2018 and in Nike's new shoes.

World Athletics set a limit of 40mm on sole thickness in January to prevent the foam-stacked shoes growing even bigger.

Both Kipchoge and Kosgei insisted that the shoes do not unfairly disadvantage other athletes.

"We live in the 21st century and we need to accept change," said Kipchoge.

"The shoes cannot run - it's the person who runs," added Kosgei.

The race goes on out of sight

Organisers considered whether there was a tracking solution that would allow the mass participation race to take place

Organisers had considered staging the mass participation event with runners wearing high-tech tracking technology to monitor how long they were in close proximity.

However, the logistics ultimately proved impossible and they are taking the race 'virtual' for the first time.

Those taking part will try to cover 26.2 miles, taking breaks if required, over the course of 24 hours on Sunday, logging their progress on the event app.

One of those taking part is Ken Jones. The 87-year-old is the oldest man in the event and will keep up his record of running in every London Marathon since the race's inception in 1981.

He will be running in the countryside around his home in Strabane. While his London Marathon personal best is 2:55:38, Jones expects Sunday's run to take him about seven hours.

"It will be a 40th race that lives long in the memory for being different, but also for being an inspirational event in these difficult times," said event director Hugh Brasher.

If you are taking part in the virtual London Marathon, send us your pictures and stories using the hashtag #bbcmarathon on Twitter or Instagram.Or contact us by texting 81111.