A "There definitely is a God" poster displayed on buses triggered more complaints than any other in 2009 and the third highest of all time, according to Advertising Standards Authority figures published today.

The battle over whether God exists helped cause a 10% increase in complaints to the regulator, to almost 30,000.

The Christian Party's poster was a riposte to the British Humanist Association's ad insisting "There is probably no God. Now stop worrying and enjoy your life". The ASA did not investigate, on the grounds that political party ads are outside its remit, though it had 1,204 complaints asserting that the existence of a divine being was offensive to atheists, and in any case could not be proven. The ASA also did not investigate the atheists' bus ad, though it was the sixth in the list of most complained about.

In all, there was a 36% rise in complaints of offensiveness, to near 12,000. At the other end of the spectrum, billboards asking "Want Longer Lasting Sex?" to sell a nasal spray, brought 500 complaints.

Thanks in part to these bus campaigns using buses, the advertising medium of transport as a medium for display saw a 267% year-on-year increase in complaints to the ASA. Complaints about billboards, which also covers posters on buses, saw a 100% year-on-year increase.

Overall the ASA, which regulates advertising across television, the internet, radio and print, said that it was just a couple of campaigns that skewed some of the complaints figures in its annual report for 2009.

While the total number of complaints was up 9.6% to a record 28,978, the number of ads complained about actually dropped by more than 10% year-on-year to 13,956. And the number of formal upheld rulings, where the ASA ordered an ad to be changed or withdrawn, also fell slightly year-on-year to 2,397.

The ASA has today banned a Eurotunnel claim in an email promotion that its service to take cars through the tunnel by train takes just 35 minutes and runs "whatever the weather".

A complainant was stranded several hours at a Eurotunnel check-in during the chaos caused by snow in December.

Eurotunnel's response to the ASA said a "reasonable" consumer would not take an "absolute view" of "whatever the weather", and the "fluffy snow" blamed for causing trains to stall and block the tunnel should be seen as comparable to a "hurricane or tsunami … as it was so unusual", and the delay would not recur. The ASA said the comparison was invalid, and a recurrence could not be ruled out.

Last year complaints about alcohol advertising, which had seen a 44% increase in 2008, plummeted by almost 50% last year. A media focus on airbrushing in health and beauty ads, a cause championed by the Liberal Democrat MP Jo Swinson who pushed for the banning of an Olay ad featuring Twiggy, saw a 52% increase in complaints about campaigns in the sector.

The number of complaints about ads on television, the most complained about medium, rose 17% last year. However the number of ads actually complained about fell 3%. The internet remained the second most complained about medium, attracting 3,546 complaints about 2,823 ads. However, the ASA said that 57% of the ads complained about fall outside its remit, which does not cover marketing claims companies make on their own websites, meaning the watchdog cannot look into them.

In 2008 the ASA was confronted with a surge in complaints about violence in advertising, mainly due to the content of ads promoting films and videogames, which the watchdog says it successfully worked with advertisers to reduce last year.