Actress and celebrity Joanna Lumley stars in a new film to launch the Richard Chartres Fund, a campaign to raise money in memory of the retiring Bishop of London after 21 years in charge.

The Absolutely Fabulous star narrates the short video showcasing different projects across the Diocese of London, held up by Church leaders as the most successful area in terms of church growth.

"Since Richard Chartres' appointment as Bishop of London in 1995, the city has changed beyond recognition," she says.

"From the dawning of the 21^st century, to the dotcom crash and the emergence of the digital revolution to mourning those we lost on 7/7; from stock market highs to catastrophic lows; from the fear of the riots to the excitement of the Olympics, the last 22 years have certainly been memorable."

"Throughout these tumultuous times Richard Chartres has helped Londoners navigate unpredictable events, provided a challenge to injustice and a consistent and dependent booming voice of truth."

Lumley was raised a Christian but described herself as a "pagan" in an interview in 2012.

"I think I'm a pagan, but a believer in all. I kind of believe in the trees. Do you know?" she told the Radio Times magazine.

"I think most of us are curious. Which is why religion is so important to people. We all want to find out "What's it all about, Alfie?" before we book out completely," she said at the time.

"I was brought up as a Christian – first in India, in a house which had all these masses of Buddhist images, in a country where Hinduism reigned – and then in the Far East where the call of the muezzin [the Islamic call to prayer] was heard every morning.

"I'm a fellow traveller with all these faiths, but I haven't got a personal tradition.

"The message I would take from the story of the flood as God's punishment is that we are all responsible for behaving properly on the planet. Look after it, because it could go badly wrong."

In the video she says: "Today presents tremendous challenge and opportunity.

She went on: "As inequality increases the church must respond."

The fund launched as Chartres retires aims to raise £1.4million for church growth across the capital.