The event on April 26, sponsored by Virgin Money, is already guaranteed the world’s full attention given that the elite men’s field includes the two fastest marathon runners of all time.

Kenya’s Rio 2016 Olympic champion and world record holder Eliud Kipchoge, and Ethiopia’s multiple world and Olympic track champion Kenenisa Bekele will go head-to-head following the latter’s addition to the field on January 17.

In Berlin last year Bekele missed Kipchoge’s official world record of 2hr 01min 39sec by just two seconds, and their meeting is sure to be compelling.

Meanwhile the women’s field will feature defending champion Brigid Kosgei of Kenya, who followed up her victory in London by breaking the 2013 world record set by Britain’s Paula Radcliffe as she won the Chicago Marathon in 2hr 14min 04sec.

Kosgei heads a stellar field that includes fellow Kenyans Vivian Cheruiyot, the 2018 champion, and world champion Ruth Chepngetich.

The 40th Race campaign was launched at a star-studded reception on Tower Bridge as a special film celebrating The 40th Race was released.

Hugh Brasher, Event Director of the Virgin Money London Marathon, said: “This year will be The 40th Race and we are so proud of how far the event has come since that wet day back on 29 March 1981.

“The London Marathon has proved to be a unique force for good and continues to have an extraordinary impact on society.”

Brasher was joined at the launch by numerous celebrity charity runners including double Olympic cycling champion Joanna Rowsell Shand, double Olympic rowing champion James Cracknell, BBC newsreader Sophie Raworth, former England footballers Danny Mills, Stephen Warnock and Karen Carney, and BBC EastEnders actress Tanya Franks.