The Advertising Standards Authority will decide next week whether to investigate complaints that a series of adverts on public transport which claim there is no God have breached the code of conduct.

The ASA has received around 250 complaints about the ads, which have appeared on 800 buses across Britain.

“There is probably no God,” they read.

“Now stop worrying and enjoy your life.”

The £140,000 campaign also uses ad space on the London Underground and two large LCD screens on Oxford Street. It will run for four weeks and has been funded by leading humanists such as scientist Richard Dawkins.

It is the UK’s first ever atheist advertising campaign.

The ASA code of conduct requires advertising to be factually correct and some Christians claim the statement should capable of substantiation to comply with the rules.

Homophobic preacher Stephen Green has complained to the ASA.

“The advertisers cannot hide behind the ASA’s ‘matters of opinion’ exclusion, because no person or body is named as the author of the statement,” he said.

“It is given as a statement of fact and that means it must be capable of substantiation if it is not to break the rules.

“There is plenty of evidence for God, from peoples’ personal experience, to the complexity, interdependence, beauty and design of the natural world.

“But there is scant evidence on the other side, so I think the advertisers are really going to struggle to show their claim is not an exaggeration or inaccurate, as the ASA code puts it.”

A small group of MPs have signed two early day motions attacking the athiest ad campaign.

So far only a total of ten members have signed the EDMs. The first was tabled by Bob Spink MP, a former Tory who was expelled from the party and now sits as an independent.

He called on ministers “responsible for public transport and advertising media to investigate this matter and to seek to remove these religiously offensive and morally unhelpful advertisementsm.”

His EDM said “many” Christian and Muslim people feel embarrassed and uncomfortable travelling on public transport displaying the ads.

Labour MPs David Drew, Jim Dobbin, Marsha Singh and Ann Cryer supported the motion, alongside Democratic Unionists Gregory Campbell and David Simpson.

Another EDM from Mr Campbell claimed the rationale behind the ad campaign is that people “can be less careful about their lifestyle choices and general approach to life’s consequences by discounting the likelihood of a Creator and an afterlife; and recommends to Christian groups considering alternative advertising approaches to There’s Probably No God to counter it with the simple addition of But What If There Is?”

Last year the ASA ruled that a Free Presbyterian Church’s church’s advert, which called gay people perverts and called on “religious” people to publicly oppose gay rights and Pride events, broke their rules on decency and went further than the majority of readers were likely to find acceptable.

“We considered that particular care should be taken to avoid causing offence on the grounds of sexual orientation, and concluded that this ad had caused serious offence to some readers.

“The ad should not appear again in its current form,” according to the ASA ruling.

The ad claimed Pride in Belfast “is not a welcome addition to our city, neither is it a positive celebration of a profitable lifestyle flaunting a form of sexuality that generations of men and women have righteously resisted and by God’s grace will continue to resist.”