London is, of course, the city where Mo Farah had arguably his greatest day - on Super Saturday in 2012.

A lot his happened since then, not least three more gold medals. There has been controversy too.

He has been speaking to Steve Cram about his career and his final marathon.

Mo Farah is expecting today to be an emotional day. It will be the last time he runs a marathon before retiring.

The four-time Olympic track champion, who turned 40 last month, confirmed in January that he expects 2023 to be the last year of his glittering career.

"It won't be my last race but London will be my last marathon," British record holder Farah said on Thursday.

"It will be quite emotional. Maybe after the race there will be tears."

A hip injury prevented Farah from taking part in last year's event and, following a frustrating couple of years, Sunday's race in his home city is set to be his first full marathon since 2019.

He is not expected to contest for podium places in the elite men's race. The Briton finished a disappointing seventh in 30 minutes and 41 seconds in the Port-Gentil 10km in Gabon two weeks ago, after training in Ethiopia.

Baroness Tanni Grey-Thompson
Six-time London Marathon wheelchair champion on BBC TV

It looks like Marcel Hug has an unassailable lead already.

There will be some concern about punctures now because of the rain. The drizzle doesn't help anybody, because it tends to wash up some grit on to the road.

The rain is starting to call in London now. There are plenty of ponchos on sight at the start line where the masses are starting their warm-ups.

The weather doesn't seem to be impacting former champion Marcel Hug in the men's wheelchair race. He has broken clear and is now out on his own.

London Marathon director Hugh Brasher on BBC One: "We have been speaking to Extinction Rebellion for months about their protests.

"Their cause is so important and we want our two parties to work together. We have had conversations with Just Stop Oil too, and again, the cause is important.

"Runners need clean air to breathe, our runners are raising money for good causes and some of those will be climate related. The conversations need to happen and action needs to happen.

"We are going to have a great day. I have no idea about what individuals might decide to do but I can say that we have put mitigations in place, we just hope that people realise how good this race is for physical and mental health and it can all go to plan as it always has done.

"For the first time ever, people are able to plant trees instead of getting a race T-shirt, we have the shirts made from recycled materials, we have electric vehicles.

"We only have one world and we have to look after it."

Image source, Getty Images

Just Stop Oil says it will "continue disrupting cultural and sporting events" amid concerns protestors will target the London Marathon on Sunday.

London Marathon race director Hugh Brasher said that he has received "unique" assurances from Extinction Rebellion over their protest already planned for Parliment Square on Sunday.

But, in an interview with the BBC, a Just Stop Oil spokesperson would not rule out disrupting the event.

Indigo Rumbelow said London Marathon runners "want what Just Stop Oil want".

She added the climate activism group's disruption would continue "until the institutions of this country pick a side".

Switzerland's Marcel Hug has hit the front of the men's wheelchair race.

He holds the course record around these streets.

Steve Cram
Marathon commentator on BBC TV

I just don't know why she lined up. We knew she had injury problems and she admitted that, so I was surprised to see her on the start line.

She has had a difficult few years with injuries.

It's really sad to see.

And it looks like world record holder Brigid Kosgei has now pulled out just three minutes in!

She has moved over to the side of the road and looks to be waiting for a lift to the finish.

There's one of the contenders out then...

Paula Radcliffe
London Marathon women's record holder on BBC TV

It's a fascinating line-up and I am really looking forward to seeing how it plays out.

It looks like Brigid Kosgei is limping already and that is not good to see this early on. There were a few doubts about her fitness ahead of this race, so that's not a good start.

I am really intrigued to see Sifan Hassan's performance as she is not used to this distance, she is a track specialist, but she said she just fancied a new challenge and what a way to do it!

Image source, Getty Images

This is why they're calling this the greatest women's distance race in history.

These ladies have more medals between them than some countries.

The hooter sounds and off they go. Next stop - The Mall.

Steve Cram
Marathon commentator on BBC TV

It's cool, and the conditions are looking good for a fast time. There may be a bit of rain and a breeze later on which could have an impact, but there is so much talent on show in this women's race.

We are expecting an absolute cracker.

Ingrid Kristiansen, four-time London Marathon winner, who broke the women's world record twice in London, in 1984 and 1985, is one of the starters of today's women's elite race.

She said on BBC One: "I think we can see a super quick time if the girls want to have a good time. They are good enough to do it but I don't know how they are thinking today.

"But the weather conditions and everything are good, so it could be a really fast race."

Image source, BBC Sport

Image source, Getty Images

In the pre-race news conference, last year's winner Yalemzerf Yehualaw was asked about the prospect of a new world record being set.

"I hope we will run a course record or a women's only world record," she said.

"I want to defend my title and I'm ready to do my best. I am in good shape."

Baroness Tanni Grey-Thompson
Six-time London Marathon wheelchair champion on BBC TV

The women's race is much harder to call than the men's, where Marcel Hug is the favourite.

But this course is very different, it's a much more technical course for the wheelchair racers than the likes of Boston, which has more downhill.

Paula Millsom: Good luck to my wonderful husband Tony running today. Raising lots of money for children with cancer. Go go go - so proud.

Hanna: Go well Mike Powell, running the marathon in memory of my awesome dad Simon Newcombe, taken too soon in January.

Annie Bayliss: Good luck to my nephew Chris Sannwald running today's London Marathon for Good Shepherd Hospice.

Here we go then.

The first races of the day are under way - the men's and women's wheelchair races.

Of course, David Weir gets the biggest cheer on the start line as he sets off for his 24th London Marathon.

The women's elite race isn't the only place we might see a world record today.

There will be 73 world record attempts today, from the inspirational to the weird and wonderful.

Radio 1 presenter and DJ Adele Roberts is attempting to become the fastest female with an ileostomy.

Royal Marine Sam Hammond is running with a fridge on his back, attempting to set the fastest time while carrying a household appliance.

There are also attempts at the fastest time dressed as a 3D dinosaur, an aircraft and crustacean, plus an attempt at the most underpants worn while running a marathon.

Image source, Getty Images

Eight-time champions David Weir is once again racing in the men's wheelchair race, competing in the London race for the 24th consecutive year.

Switzerland's Marcel Hug, the defending champion and a dominant winner in Boston, is favourite, however, along with American Daniel Romanchuk.

43-year-old Weir will be racing as hard as ever, of course, but does have other things on his mind this year.

Eden Rainbow-Cooper is one of the leading contenders in the women's race after coming through the Weir Archer academy, which was set-up by the former Paralympic champion and his long-time coach Jenny Archer.

Rainbow-Cooper finished third last year and is looking to challenge again.

"I knew from early on in Eden's career that she could be a good long-distance racer and that she could do the marathon distance, but she is also a good track racer," Weir said. "I can see a lot of me in her.

"What she did last year was truly amazing and I hope that she can have a good race and try to finish in the top three again."