London — You're drinking with friends in a pub in London's lively West End when a catchy tune comes on the jukebox and you begin swaying to the music. Stop right there — you might be on the verge of breaking the law.

A British pub chain was fined £5,000 ($12,500 Canadian) after undercover inspectors caught a few patrons dancing at two of its popular bars. The crime: flouting licensing laws that ban "rhythmic moving."

Another pub where customers were found "swaying" was served two written warnings.

Under British law, dancing is allowed only in pubs that have public entertainment licenses. Getting the licence from local governments can be an expensive and overly bureaucratic process, however, so only about 5 per cent of pubs, restaurants and nightclubs currently allow live entertainment and dancing.

"We have spent ages trying to stop people dancing. We have signs up everywhere. Managers instruct customers. We turn the music down, rearrange the furniture and so on," said Derek Andrews, spokesman for Wolverhampton & Dudley Breweries, owners of the Pitcher & Piano chain, which pleaded guilty to the offenses at a London magistrates court Wednesday.

Undercover inspectors from Westminster Council spotted a clear breach when they paid a visit to a Pitcher & Piano bar in the West End and found four people dancing to recorded music.

A return visit to the same pub caught another five people in the act, while a check on another Pitcher & Piano bar discovered a group of 11 drinkers indulging in "rhythmic moving."

For those unsure about whether their movements constitute dancing, Westminster Council believes the rules are clear.

"Dancing could be described as the rhythmic moving of the legs, arms and body, usually changing positions within the floor space available and whether or not accompanied by musical support," Bob Currie, director of the council's community protection department, said in a letter to an industry newspaper, The Publican.

Westminster Council said the two pubs had ignored advice that they were encouraging dancing and should apply for an entertainment licence.

Without the licence, they are also forbidden to allow more than two musicians to perform at the same time.

The British government proposed changes to the licensing laws last week that would allow pubs to stay open later than the traditional 11 p.m. closing time, but the proposals do not address dancing.

Mr. Andrews insisted that Wolverhampton & Dudley tried to comply with all the "minute details" of the licensing laws.

He said: "On a personal note, I would like to say that, to the best of my knowledge, spontaneous dancing is not in the top 10 lists of great social ills of our time."