BRITISH atheists have been celebrating the appearance of flippant slogans on London buses this week but atheists in Australia have been barred from launching a similar advertising campaign on the nation's public transport systems.

The Atheist Foundation of Australia was knocked back by Australia's biggest outdoor advertising company, APN Outdoor, on its proposal for a nationwide campaign featuring atheist slogans.

The campaign - with slogans such as "Sleep in on Sunday mornings" and "Celebrate reason" - follows successful attempts by the British and American Humanist Associations to raise awareness for atheism in London and Washington.

APN Outdoor cited no reason for rejecting the $16,000 public transport campaign, and declined to comment.