British spirits naturally high at Christmastime. In fact, fewer Britons are imbibing all year round

The Christmas message from Britain this year is ``somber and sober.'' Somber because the weather forecasters see only a bleak, dull, wet Christmas for most of the country, with little prospect of a Bing Crosby white Christmas to dream about.

Sober because marketing surveys show that fewer people are looking to alcoholic beverages as one of the ways to celebrate this festive season.

A survey of 20,000 people prepared for the Brewers Society shows that 14.9 percent of the population here are now teetotalers, compared with 12.5 percent six years ago. The biggest rise in nondrinkers - from 6 to 8 percent - is among people between the ages of 25 and 34. The survey also reveals that much greater stress on health, exercise, and diet apparently lies behind the decisions to abstain.

Although Britain is not a heavy wine-drinking country compared with, say, Italy or France, the popularity of the British pub means beer is quaffed in vast quantities. So much so that Britain is often referred to as a ``beer culture.''

A decline in sales of alcoholic beverages - for example, an 11 percent drop in beer sales since 1980 - by no means implies any lessening of Christmas festivities in Britain.

Britons enjoy hearty Christmas meals and then take Boxing Day, Dec. 26, off as it is a recognized public holiday for recovery from the annual Christmas rush. This means that most offices here will close around midday on Wednesday and not reopen until the following Monday. British industry goes one better: It closes down until after the New Year.

The Christmas period, and particularly Boxing Day, is an opportunity for most Britons to go on a family spree to the theater.

Those wishing to make last-minute arrangements to see Shakespeare's King Lear, either on Boxing Day or over the New Year holiday, will be disappointed. King Lear is playing to packed houses after rave reviews. In particular, superlatives have been showered on lead actor Anthony Hopkins. So great is the demand for seats that it is not possible to get a ticket until next April.

Those looking for something a lot lighter than King Lear can indulge in the British penchant for pantomimes, which are a feature of the Christmas entertainment season.

These productions are, in fact, not mime at all, but boisterous shows, with audience participation. They are freely adapted from children's nursery stories and updated with broad modern humor and musical numbers.

It is a tradition in pantomimes that the leading man, such as Jack in ``Jack and the Beanstalk,'' is played by a young woman usually with close-cropped hair and wearing a tunic. Men, in turn, are cast in such unattractive roles as the Ugly Sisters in Cinderella. And, accompanied by much audience booing and hissing, there is always an arch villain, usually given some horrendous name such as Fleshcreep.

The villain, of course, is frustrated in his evil endeavors. The children squeal in delight. And the show ends on a hopeful, upbeat note that leaves the audience streaming out of the theater feeling suitably uplifted for the Christmas season.