The London Marathon has followed the Boston Marathon in postponing the 2020 race because of the coronavirus pandemic.
In a statement, London Marathon organisers announced the race had been pushed back from April 26 to October 4.
That decision comes after those in charge of the Boston Marathon opted to move that event from April 20 to September 14.
Hugh Brasher, event director for the London Marathon, said: "The world is in an unprecedented situation grappling with a global pandemic of COVID-19 and public health is everyone's priority.
"We know how disappointing this news will be for so many – the runners who have trained for many months, the thousands of charities for which they are raising funds and the millions who watch the race every year.
"The 40th race is scheduled to go ahead on Sunday 4 October 2020.
“We know that there will be many, many questions from runners, charities and others and we ask you to please bear with us as we work through the detailed planning process to deliver the 2020 Virgin Money London Marathon on its new scheduled date."