Health organisations are furious that a major tennis tournament in Switzerland is being sponsored by one of the world's leading cigarette companies.

Davidoff, the brand that covers luxury items from cigarettes and cigars to aftershave, will be the main sponsor at the Basel ATP World Tour 500 tournament. The Davidoff cigarette brand is owned by Imperial, which is the fourth largest cigarette company in the world.

Tobacco advertising has been banned by the EU in all its member states since 2005, but Switzerland is not in the EU, thus the sponsorship is legal.

Today, the health detriments of smoking are widely advertised and the government has come a long way in changing our behaviour and attitude towards smoking. As well as bans on tobacco advertising, the UK has seen bans on smoking in public places, an increase in the age for the legal purchasing of cigarettes - from 16 to 18 and graphic picture warnings on the packets of cigarettes.

And this decision has incensed the World Health Organisation, as well as European campaign groups, such as the UK's Action on Smoking and Health (Ash).

The satellite broadcaster Eurosport has dropped plans to show the event after French anti-tobacco campaigners threatened legal action and a letter, signed by more than 500 significant health experts has been sent to Roger Federer, the Swiss world number one calling for him to pull out of the tournament, though as yet, Federer has declined to respond.

In addition to this, Unesco, the UN's cultural arm, which received a donation from the event's organisers, has returned the money and demanded it no longer be associated with the tournament. A spokesman for Imperial declined to comment.