Organisers of the culture festival, Simcha on the Square, hope to run the event in Trafalgar Square again next year, despite fears of funding cuts.
SOTS director Geraldine Auerbach said larger contributions from the Jewish community would be needed because of a reduced grant from the Greater London Authority.
This year the GLA provided £48,000 towards the event, which costs around £100,000 to stage.
A spokesman for London Mayor Boris Johnson said money would remain available and that City Hall intended to help fund the event in 2009, but could not confirm the exact amount available.
Last week, Mr Johnson's marketing adviser, Dan Ritterband, told a GLA budget meeting that the mayor's office wanted to avoid "groups coming to us and saying ‘we want this much" and instead to help organisations increase funds raised through sponsorship.
Mrs Auerbach said: "We have been in contact with the mayor's office and they really want Simcha to happen, but there may be less funding.
"It is seen as a good bonding event that shows the Jewish community to Londoners in a very open and fruitful way. I hope the community will back Simcha in the way both Ken Livingstone and Boris Johnson have done.
"We want to encourage people to say ‘wow, what an operation this is', and then match the GLA money."
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