Atheist adverts declaring "there's probably no God" could be placed on buses across the country after a fundraising drive made five times the target amount in just one day.
Even religious groups donated money to the cause in the belief that the campaign, highlighted in The Daily Telegraph, would encourage people to think more about faith and could actually enhance support for Christianity.
Organisers needed to raise just £2,750 from supporters in order to pay for adverts doubting the existence of God to be plastered across 30 London bendy-buses for a month, after the prominent atheist Professor Richard Dawkins agreed to match all donations. Previous attempts to raise the money had failed.
But the £5,500 target was met within minutes of a page being launched on the fundraising website Justgiving on Tuesday, and after a few hours more than £31,000 had been given to the Atheist Bus Campaign – over five times the amount required.
Now there are plans to get the message – "There's probably no God. Now stop worrying and enjoy your life" – put on buses across Britain as well as on Tube trains in the capital.
The campaign was launched after Ariane Sherine, a comedy writer, called for a "reassuring counter-advert" to religious posters on public transport that atheists believe "threaten passengers with eternal damnation".
She said: "This is absolutely brilliant and I'd like to thank everyone who donated for their support. The sky's the limit for atheists even if we don't believe there's anyone up there."
Hanne Stinson, chief executive of the British Humanist Association, which is handling the donations, added: "If the money keeps pouring in we can expand the campaign, not just to ads inside the buses as well as outside, but to ads on the Tube or other transport, and in locations outside London."
One of the more unlikely donors was the religious think tank Theos, which was set up two years ago with the support of the Archbishop of Canterbury, Dr Rowan Williams, and the head of the Roman Catholic Church in England and Wales, Cardinal Cormac Murphy-O'Connor.
Theos gave £50 to the cause as it believes the "weak" adverts will encourage people to think about God.
Its director, Paul Woolley, said: "Initially, we almost felt sorry for the campaign, as its difficulties showed that there were not many atheists in Britain, and certainly not many who were willing to put their hands into their pockets. But when we saw the message, we couldn't believe it.
"Stunts like this demonstrate how militant atheists are often great adverts for Christianity."
The Rev Jenny Ellis, spirituality and discipleship officer of the British Methodist Church, added: "This campaign will be a good thing if it gets people to engage with the deepest questions of life."
Advertising company CBS Outdoor is set to put first run of the posters on a fleet of 30 bendy-buses that travel through the central London borough of Westminster in January, although the exact routes have not yet been decided.
Tim Bleakley, the firm's managing director for sales and marketing, said: "It's not for us to make judgments on the appropriate nature of advertising based on people's beliefs, but we are pleased to see people engaging and reacting to outdoor advertising.
"Ultimately, CBS Outdoor is a commercial media business that generates revenue from advertisers, and we are completely neutral in every respect. As such, our decision to take an ad that promotes God, or one that promotes No God, is based on commercial terms, as long as the advertising copy itself does not breach UK advertising standards."