British atheists have raised a pile of cash to tell Londoners there's probably no God and to get on with life.

The nation's first atheist advertising campaign has beaten its funding target in less than 24 hours, raising nearly nine times the amount it needed to posts its ads on public buses in London.

Organisers hope to run more than 5,000 ads in the city over a month, telling people: "There's probably no God. Now stop worrying and enjoy your life''.

By last night, less than a day into fundraising efforts, pledges of more than 47,900 pounds (NZ$132,000) had rolled in, organisers told The Guardian newspaper.

Writer Ariane Sherine suggested the idea in a blog carried on The Guardian website last year.

She believes an atheist advertising blitz will provide a reassuring counter-message to religious slogans threatening non-Christians with hell and damnation.

"Ours is a fun and light-hearted message but it does have a serious point to it - that atheists want a secular country, we want a secular school and a secular government,'' she told The Guardian.

"The strength of feeling has been shown with so many people willing to pay for this campaign.''

Sherine said she was surprised and pleased with the level of support, and the extra cash would fund a more ambitious ad campaign.

"We could go national, we could have tube posters, different slogans, more buses, advertising inside buses. The sky's the limit - except, of course, there's nothing up there,'' she said.

A spokesman for the Church of England said seven in every 10 people in Britain described themselves as Christian and understood the joy faith could bring.

"Christian belief is not about worrying or not enjoying life. Quite the opposite: our faith liberates us to put this life into a proper perspective,'' he said.

The bus ads will begin to run in January.

 

- AAP