London — The sudden chill in the air here is the signal for British holidaymakers to fold up their summer tents and leave the deserted seaside resorts to the politicians.
Autumn is traditionally the time for Britain's political parties to hold their annual conferences.
Beginning with this week's Social Democratic Party convention and continuing through the middle of October, when the Conservatives wind down the conference season, the British public will be bombarded by party political slogans.
Nearly all the parties head for the coast, as the Labour Party's new leader, Neil Kinnock, remembers only too well. Posing for photographers last year, he stepped unsuspectingly back into an approaching wave, but recovered nicely by conceding he could not walk on water.
The four mainstream parties have chosen as their venues this year Blackpool, Brighton, Bournemouth, and Buxton.
Blackpool, Brighton, and Bournemouth are popular coastal resorts whose accommodations range from high-class hotels to myriad boardinghouses strung along the seafront. All offer a gargantuan English breakfast of eggs, bacon, sausage, fried bread, grilled tomatoes, and occasionally, mushrooms and kidneys as well.
Only the Social Democratic Party has opted to go inland - to Buxton, in Derbyshire, a county with some of England's loveliest countryside. But that puts it off the beaten track for a conference. Buxton has no airport and is away from the fast motorways.
Not surprisingly, when asked about Buxton, a Cockney attendant at British Rail's office at London's Waterloo Station replied: ''Never 'eard of it.''
Those coming to the conference by rail must disembark at Macclesfield in Cheshire and proceed by bus to Buxton some 20 miles away. The logic for holding a conference there is that the town lies about halfway between London and the Scottish border.
The choice of Brighton and Blackpool for the two major parties, the Conservatives and Labour, is predictable.
With scrupulous impartiality, whichever of those two parties has gone to Brighton one year has visited Blackpool the next. Thus it is the Conservatives' turn to go to Brighton this year, while Labour is heading for Blackpool.
In a break with tradition, Labour will be booking into Bournemouth next year, a south coast resort that happens to be this year's venue for the Liberal Party.
That Labour Party switch from Brighton will come as something of a disappointment to journalists who enjoy contrasting Brighton, a prime resort in the south that is middle to upper class and solidly Conservative, with Blackpool , a jaunty northern, working-class seaside resort best known for its brilliant beach-front illuminations.
Predictably, Brighton is where the Conservatives feel most comfortable, while Labourites feel more at home at Blackpool.
Here is a brief synopsis of the conferences and what may be in store for party delegates:
Social Democrats, Buxton, Sept. 9 to 12: The SDP is trying to regain its high-water mark of two years ago when it appeared to be ousting the Labour Party as the principal opposition.
It has since won some spectacular by-elections and made gains in local government elections, but it has lost noticeable momentum in recent opinion polls.
Liberals, Bournemouth, Sept. 17 to 22: Liberals who do not always see eye to eye with their election partners, the SDP, on defense issues and ways to end the coal strike have to struggle with how well they can walk with the SDP under the alliance umbrella.
Liberal leader David Steel tends to be overshadowed by SDP leader David Owen, who has been quick off the mark in scoring debating points against all contenders on issues in the news.
Labour, Blackpool, Oct. 1 to 5: Most of the focus will be on new party leader Neil Kinnock. Philosophically a left-winger, he has been shrewd enough to realize he must occupy the middle ground if he is to lure back those Labourites who were disenchanted with its recent shift to the left.
The conference will give some clues as to how well Mr. Kinnock can straddle the Liberal line between left-wingers who want to democratize the selection of candidates and right-wingers who are convinced that rank-and-file enthusiasm for unilateral disarmament would lose the party the next general election.
Conservatives, Brighton, Oct. 9 to 12: Conservatives generally do a better job than Labour in publicly proclaiming their unity. Prime Minister Margaret Thatcher had looked particularly vulnerable last summer when the British economy came under sharp attack, but her position within the party and the country as a whole appears unassailable, and the next election is a long way off.