RIZLA cigarette papers are to carry warnings that excessive cannabis smoking makes you incredibly boring and likely to bore others around you.

The warnings follow new research into the dangers of so-called 'passive tedium' which show that people exposed to cannabis smokers are often incredibly bored by the experience.

Professor Henry Brubaker, of the Institute for Studies, said: "You may think that your incoherent theories about the nature of music are interesting. But the fact is, they are unbelievably boring and you have to shut up."

He added: "The danger is other people become so bored they start to throw up and before you know it you have to make yourself look interesting by growing dreadlocks.

"It's about as cutting edge and rebellious as my Gran. Reggae? Thump, thump, thump. Batty boys, Mr Bombastic. What a lot of pish."

A series of warnings will be printed on each individual Rizla paper including:

Smoking cannabis while pregnant will make your baby boring

Cannabis smoking will lead to a slow and painful conversation

Don't stab people in the eye when you go all psycho and shit

Health minister Alan Johnson said that every day cannabis smoking bores 19,000 Europeans who don't smoke cannabis.

He added: "We're urging moderation. There's no need to roll a really fat one first thing in the morning, unless you have a stressful job like driving a train."