London Marathon entrants from the Jewish community have raised hundreds of thousands of pounds for charity. But the total looks likely to be much lower next year.
This is because the marathon organisers have decided to hold the 2016 event on April 24, the second day of Pesach, ruling out the participation of Orthodox runners.
In a letter to The Times on Wednesday, Board of Deputies chief executive Gillian Merron and leaders from organisations including Kisharon, Wizo UK, World Jewish Relief, Emunah and Masorti Judaism wrote that the timing "will prevent many Jewish runners from participating and prevent many Jewish charities from benefiting".
The Board has also written to Nick Bitel, the marathon's Jewish chief executive, to express disappointment at the chosen date, one of three which had been under consideration.
Great-grandmother Flora Frank, who ran her 19th London Marathon for Emunah and Norwood, is one who will not participate next year.
‘This will prevent many Jewish runners from participating’
"I can't believe they're going to do that," she said. "This is a multi-cultural society and they should take Orthodox Jews into account.
"All these wonderful charities are going to miss out. It's a great shame."
Special needs charity Kisharon, which mainly works with Orthodox children and earned £24,000 through its marathon team this year, said it would be deprived of "a five-figure sum".
Mr Bitel, who is also chair of Sport England, accepted that the choice of date would be "disappointing" for some charities and potential runners. He pleged to soften the blow by adding any unfilled places to affected charities' 2017 allocations.
"I'm afraid it's part of the issues of living in a pluralistic society," he added. "Clashes sometimes can't be avoided."
Norwood was the largest communal beneficiary of this year's race, with an £80,000 total, which chief executive Elaine Kerr called "fantastic".
The money would "greatly benefit the thousands of vulnerable children and their families, and the adults we support."
Ms Merron said the marathon has been "completely embraced" by the community, both for Jewish and secular charities.
"It is wonderful that so many Jewish people ran in this year's race and raised such a significant amount for worthy causes."