The party political leaders are the latest public figures to throw their weight behind this year's Mitzvah Day, the community's national day of volunteering.
David Cameron said: "National Mitzvah Day is a great example of how faith communities across the country are contributing to furthering social responsibility."
Labour leader Ed Miliband said: "Mitzvah Day volunteers will show that the age-old Jewish imperative of Tikkun Olam, changing the world for the better, is as powerful today as it ever was."
From Nick Clegg there was a "wholehearted endorsement of Mitzvah Day, especially the efforts to involve other faith communities".
Mitzvah Day founder and director Laura Marks said she was "absolutely thrilled to have the support of the leaders of all three main political parties".
Events will be taking place in many smaller communities including Harlow, Stevenage and Cardiff and also internationally in places from Vilnius, Bratislava, Gaborone, Harare, Lusaka and Windhoek. Ms Marks added: "There are many small communities who are isolated. Our strategy is to bring something constructive and collective to these communities so that we can strengthen our community as a whole and, at the same time, facilitate more social action and interfaith relationships."
Around 25,000 volunteers are expected to take part in events on Sunday. London Mayor Boris Johnson and former Prime Minister Tony Blair have also voiced their support for the scheme.