Archbishop of Canterbury Dr Rowan Williams and London Mayor Boris Johnson are supporting the final push for Mitzvah Day, Sunday's community-wide volunteering initiative.
Dr Williams says "the Jewish community should be proud of what they achieve each Mitzvah Day. I am also proud that increasing numbers of Anglican groups are joining our Jewish friends, both to build bridges and to make a difference to those in our community who, from time to time, need a helping hand."
Mr Johnson describes the day as an example of the community spirit he wants to see across the capital.
"Sometimes we forget that the most precious commodity we can offer to make the lives of those around us that little bit better isn't the money in our pockets, but the time that we can give - and this superb initiative epitomises this."
Participants will be from across the age spectrum. For example, the 22nd North Leeds (Hillel) scout troop is putting on a campfire concert for Jewish home residents. And Stonegrove and Bushey Jacs members - many well into their 80s and 90s - have completed their Mitzvah Day activity early, collecting spectacles for people in the developing world.