Mitzvah Day founder and chair Laura Marks concedes that her yearly summation is always "it's the best yet". But with an estimated 40,000 people around the globe participating in the tenth edition - 25,000 in the UK - Ms Marks argues that "it is not only the numbers but the quality of projects" that demonstrate the progression of the day of good deeds.

"We have come a long way in 10 years. This is the biggest collective team event."

Of the 550 Mitzvah Day events worldwide, around 350 were in the UK, stretching from Exeter to St Andrews. Ms Marks - who spent Sunday visiting a variety of events in north London and the Hertfordshire suburbs - praised the commitment of local project co-ordinators. "It would not happen without them," she said.

In one of the day's standout activities, Chief Rabbi Ephraim Mirvis joined the Muslim Council of Britain's Imam Ibrahim Mogra, MP Luciana Berger and Jewish and Muslim youth at Edgware Synagogue, preparing food for a homeless shelter.

London Mayoral candidate Sadiq Khan, MP, had a busy day, packing parcels for the elderly at Belsize Square Synagogue, helping West London Synagogue and St Paul's Church members to cook lunch for local residents and collecting goods in Oxford Street for the shelter at King's Cross Methodist Church.

Northwood and Pinner Liberal Synagogue hosted a past and present refugee day with speakers ranging from those who survived the Holocaust to Syrians who have fled the current conflict. The shul was also a hub for donations from local churches and mosques.

Innovations that particularly pleased Ms Marks were Mitzvah Day Active, involving groups of non-affiliated younger people, and setting up the day in "places you don't really think of as Jewish" - Poland, for example.

Bridges built with other faith organisations at local and wider level had led to year-round engagement in areas such as interfaith dialogue and supporting refugees.

Two post-Mitzvah Day projects will be respectively led by Christian and Muslim women.