The total sum raised for good causes by London Marathon runners will reach £1 billion at this year’s event.

Hugh Brasher, event director of the Virgin Money London Marathon, said: “The London Marathon has set a world record for fundraising for an annual one day event every year since 2007, with an incredible £63.7 million raised from the 2018 event.

“That brought the total raised since 1981 to more than £955 million and on Sunday April 28, 2019, in the 39th London Marathon, we will break the £1,000,000,000 mark.”

Mr Brasher thanked everyone who had played a role in the race since it began in 1981, adding: “This is a phenomenal achievement and part of what makes the London Marathon unique.

“No other mass participation event comes anywhere near this kind of fundraising.”

Alzheimer’s Society and Alzheimer’s Research UK have joined forces to become the marathon’s charity of the year for 2019 with the Dementia Revolution campaign which aims to raise £3.5 million towards the UK Dementia Research Institute.

Almost one million people in the UK are living with dementia and the campaign aims to find better treatments and a cure.

Among the runners supporting Dementia Revolution are friends and family of Dame Barbara Windsor who was diagnosed with Alzheimer’s in 2014.

Scott Mitchell, the husband of the Carry On and EastEnders actress, is part of a team including several EastEnders cast members who are running as Barbara’s Revolutionaries.

Scott Mitchell
Scott Mitchell will run as part of a team including several EastEnders cast members (John Stillwell/PA)

Mr Mitchell, who will be running his first marathon, told the Press Association during a lunch to launch the 2019 event his wife’s illness is “heartbreaking’.

“They are the same person but little by little that person is starting to disappear,” he said.

“The symptoms aren’t any easier because she’s a well known celebrity.”

Mr Mitchell said it was important to raise money to fight dementia but also to get people talking about the illness.

Nell McAndrew
Model and presenter Nell McAndrew at the Virgin Money London Marathon VIP lunch (John Stillwell/PA)

Other famous faces taking part this year include model Nell McAndrew, BBC news presenter Sophie Raworth, Olympic gold medal cyclist Dani Rowe and soprano Laura Wright.

The elite races will include defending champions Eliud Kipchoge and Vivian Cheruiyot as well as Sir Mo Farah.

David Weir is hoping for a 9th win in his 20th successive London Marathon wheelchair race.

David Weir
David Weir crosses the line to win the men’s wheelchair marathon ahead of Switzerland’s Marcel Hug in 2018 (PA)

Weir, from Wallington, south London, said the race is special to him and is the only race he looks forward to every year.

“I just feel proud I have not missed one,” he said.

Virgin Money, which has sponsored the event since 2010, has agreed to extend that support until 2021 so applications for the 2021 charity of the year are now open.

The event’s 2020 charity will be Mencap.