A campaign promoting atheism through ads on public buses in London has spread to the Spanish cities of Barcelona and Madrid, igniting a controversy among the inhabitants of both cities.

The so-called “atheist buses” in London were inspired by columnist Ariane Sherine of The Guardian and backed by the British Humanistic Association and Professor Richard Dawkins.  Soon after philosopher, Anthony Grayling, journalist Polly Toynbee and the British Atheistic Association also voiced their support for the campaign.

The campaign now has some $250,000 in donations and has spread to other British cities, where some 600 buses carry ads that read, “There’s probably no God. Now stop worrying and enjoy your life.”  On Monday 1000 ads will be posted on London’s subway network.

Now, the Spanish media is reporting that “atheist buses” are circulating in Barcelona, and the Madrid city government said it would not oppose the ad campaign as long as it does not violate any advertising norms.