Around 300 people from London's religious communities explored ways of co-operating on social projects at a conference hosted by Mayor of London Boris Johnson on Tuesday.

The event was organised by Jewish philanthropist Maurice Ostro, vice-chairman of the Council of Christians and Jews and chief executive of the Fayre Share Foundation, in conjunction with the Faiths Forum for London.

Alex Goldberg, co-chairman of the forum, said its purpose was to "get faith leaders, business and local government together to look at ways we can collaborate in a time of economic downturn".

He added: "We feel that faith communities, which have always had the power of innovation and volunteering in the social field, can be a driving force for good for London."

Jewish delegates ranged from Mitzvah Day founder Laura Marks to Melanie Danan of strictly Orthodox charity, the Interlink Foundation, and Daniel Raphael Silverstein, organiser of Muslim-Jewish dialogue for young people.

Chief Rabbi Lord Sacks has become one of the first contributors to a new "social financed bond" launched by the forum. It wants to raise £500 each from 500 religious institutions to fund small grants for welfare projects.