BRITAIN'S COMMUNISTS STIFFEN UPPER LIPS

In its heyday, Britain's Communist Party flourished with tens of thousands of members and supporters. But today it is rethinking its future in light of the recent events in Eastern Europe.

Delegates to the 41st congress of the party in London last month voted to scrap a hard-line Marxist manifesto and replace it with a softer document stressing the need to abandon the class struggle, accept democracy, and adapt to social and political change in a European setting.

A new leader will be chosen in January to replace retiring Gordon McLennan, who has been general secretary for 14 years.

The Communist Party of Great Britain (CPGB) was suffering from declining numbers before Soviet leader Mikhail Gorbachev launched his reforms in the Soviet Union. The recent collapse of communism in Poland, Hungary, East Germany, and Czechoslovakia has forced the leadership to ask searching questions about the party's political relevance.

Martin Jacques, a member of the party's executive committee and editor of the monthly magazine Marxism Today, says: ``Events in the Eastern bloc have spelled the end of the communist system as we have known it: the central plan, the authoritarian state, the single party system, the subjugated civil society. Stalinism is dead and Leninism has also had its day.''

The CPGB, he says, is fighting for survival. Membership figures for the CPGB, which will mark its 70th anniversary next year, bear Mr. Jacques out. The party today has 7,500 members. In the 1945 general election it polled more than 100,000 votes and won two seats in Parliament.

Then came the 1956 Hungarian revolution which prompted mass resignations from the CPGB, and 12 years later the Prague Spring. Ten years ago the party claimed 26,000 card-carrying members. Today, besides the CPGB, there is a rival Communist Party of Britain with about 1,000 members, and a Trotskyite Workers Revolutionary Party.