British trade unionists rally 'round the myth of the 'Tolpuddle martyrs'

England's trade unionists are paying tribute to six of their most famous predecessors - the ''Tolpuddle martyrs'' - at a moment when industrial relations are in turmoil and the future of trade unionism is in doubt.

It was 150 years ago in the Dorset village of Tolpuddle that half a dozen farm laborers swore an oath under a sycamore tree and were ''transported'' to Australia for seven years as punishment. Ever since, the fate of the martyrs of Tolpuddle has symbolized the pressures under which trade unionism in this country has had to operate.

This year the annual commemoration of the great injustice has a special significance and flavor. The sleepy community of Tolpuddle, with its village green, white-painted thatched cottages, and famous sycamore (now supported by stakes), has been visited by angry politicians and union leaders determined to link the myth of the martyrs to the realities of the present day.

For Britain is in the grip of a coal miners' strike, now well into its 18th week, which is generating great fury and violence. Key British ports were shut down by dockworkers Tuesday in a dispute linked to the miners' strike.

The situation seems, on the face of things, to be a confrontation worthy of the Tolpuddle tradition.

The Marxist miners' leader, Arthur Scargill, has verbally assailed the ''social forces'' that place the working man at a disadvantage in his dealings with employers.

The leader of the Labour Party, Neil Kinnock, journeyed to Tolpuddle and spoke of ''an angry summer'' in which justice and democracy were under assault. He got huge cheers from trade unionists when he claimed that today's employers were descendants of those who in 1834 had attempted to kill trade unionism and democracy in their infancy.

Like all myths, that of the Tolpuddle martyrs is not quite what it seems. The six men who were shipped to the Antipodes (and were pardoned two years later) had not been involved in a strike. They had wanted to belong to a trade union (something which by then was legal) but had ill-advisedly run foul of ancient laws forbidding the administration of secret oaths.

It was only after a public outcry about the severe punishment they received that the martyrs began to enter mythology. After their pardon, only one decided to return to Tolpuddle. The rest, after sampling Australia, moved on to Canada.

But the folklore that encrusts their memory remains powerful. The famous sycamore, with its artificial support, is seen by some antiunionists as an apt symbol of the plight in which trade unionism finds itself.

Leaders of the movement are having to contend with the Thatcher government and its barely concealed antipathy to trade unions. In its first five years, the government has passed two laws limiting the powers of trade unions. It will soon pass a third.

Economic recession has presented union leaders with a major problem: They are having to learn to live with unemployment hovering above 3 million.

It is perhaps a sense of helplessness in the face of economic adversity, together with the government's firmly stated belief that there are limits to what unions should be allowed to do, that has begun cutting into membership.

The country's largest union, the Transport and General, has lost 20 percent of its members in the past five years. Apathy is afflicting other, smaller unions.

None of this means that 1984 will be the last year that the Tolpuddle martyrs are celebrated. The tradition is strong, and there is enough romance latent in the tale to keep the myth alive.

Significantly, perhaps, when Mr. Kinnock visited Tolpuddle this year he presided over the planting of a new tree near the sagging sycamore. What the movement needs, he seemed to be saying, was a fresh start and the strong growth of a newly planted sapling.

There are many Britons, in and out of the trade union movement, who would agree with him.