An e-cigarette led to confusion on the M6. But what are the rules of smoking fake fags?

A misunderstanding over an electronic cigarette caused a major terrorist alert on the M6 Toll motorway yesterday. The incident showed what a novelty e-cigarettes are to many people and how easily confusion can develop.

But the "fake cigarette" also raises questions of etiquette. Even before the smoking ban, a restaurant-goer lighting up would annoy fellow diners. Since the ban, such behaviour would cause consternation among customers and lead the owner to fear legal action.

Smoking an e-cigarette, however, is legal in public places. Although it contains nicotine, there is no burning and only odourless steam is produced.

The health advantages of e-cigarettes over tobacco smoking have attracted celebrities including Leonardo di Caprio and Kate Moss.

Image caption Reports of "vapour" escaping from bag on the Megabus prompted police swoop

However, some airlines have decided to ban them. There is a fear that they might unsettle passengers or cause people to think that smoking real cigarettes is allowed. Ryan Air allows e-cigarettes but also sells its alternative - a cotton bud soaked in nicotine.

It shows that perception, not only health, is a factor. For smoking is generally frowned upon these days.

So is it socially acceptable to take a battery assisted puff on a train or in a public library? And what about in the office or at a dinner party?

Damien Scott, commercial director of Skycig, a UK brand that claims to have 70,000 customers advises people to use their discretion. "They're not covered by the smoking ban. But use your discretion in public places. In enclosed spaces you should ask permission first so that you're not exhaling vapour everywhere."

Cultural commentator Peter York says there's an amusing defiance about electronic smokers. "It's quite a good joke - although obviously not on motorway buses."

But York senses that trying to puff on one at a smart restaurant might alarm fellow diners and create a scene. "If you're going to do it you should arm yourself with the legal rubric so that you can say, for example, 'under section 16 of the bill' - or whatever it is - 'I'm completely legal'."

Simon Clark, director of smoking lobby group Forest, says e-cigarettes are perfectly appropriate for restaurants. "I cannot see why you shouldn't. They're giving off a bit of water vapour but it's nothing to concern anyone."

But body language expert Judi James says people should tread carefully. Even someone putting an unlit cigarette in their mouth can upset people nowadays, she says. Anyone wanting to smoke an e-cigarette at work should inform colleagues first what they're doing.

In a restaurant it's more complicated. Short of getting up and announcing to the assembled diners that it's a "fake fag", it may be necessary to go outside. "These days the baddies are the ones smoking the fags. So I almost feel these fake cigarettes have got to be smoked in a smoking area."

What happened Find more detailed BBC coverage of the M6 Toll incident here.

Sunday Times columnist Rod Liddle, who smokes conventional cigarettes, has little time for e-cigarettes. "They're effete and cowardly." The ban on flights is absurd but then people should either give up or show some willpower if they need them so much, he argues. "They're a demonstration of craven addiction."

So if he hosted a dinner party and someone asked to smoke an e-cigarette what would he do?

"It is inconceivable that anyone I'd invite would own an electronic cigarette. But if they did I would sit close and blow smoke at them."

Others are more tolerant. "It's a bit of fun, it's a novelty," says Peter York. "If it weans people off real cigarettes, then that's a good thing."