Vienna — The trial of one of the founders of Solidarity could spark further resistance to the Polish government's new labor unions. Anna Walentynowicz, who is to appear March 9 before a local court at Grudziadz, near Gdansk, is charged with organizing a strike after martial law was imposed in December 1981 and resuming union activity on her release from internment last August.
She and Lech Walesa were among the founders of a ''free trade union'' at Gdansk in 1970. And her dismissal from her job as a crane operator in the Gdansk yard was one of the final sparks for the August strikes.
For the union's rank and file she has continued to symbolize all Solidarity stood for. Mr. Walesa is said to be planning to attend the opening day of her trial.
The authorities' decision to proceed with the trial has heightened fears that a major new move to discredit Solidarity has begun. The new unions with which the government would like to replace Solidarity have failed to win popular support.
But it may be part of a mopping-up operation through which the regime hopes to head off an expected new hard-line challenge when the Communist Party Central Committee meets next month. In recent months, dogmatists have stepped up old pressures.
It is being said in Warsaw that a trial of five leaders of the Workers' Self-Defense Committee, known as KOR, may open before then.
Recently a flurry of moves has been made against union figures: A three-year sentence was handed down at Katowice last week; five former union activists are on trial in Elblag; former internee Jan Malachowski, a well-known radio journalist and Solidarity official, has been taken into custody.
More and more the question is being asked: Is Poland going to take the kind of ''hard'' consolidation line adopted in Czechoslovakia after the crushing of the 1968 reform movement?
Or, is it to follow the moderate - and more successful - line of conciliation and tolerance pursued by the administration in Hungary?
Many in Poland believe Gen. Wojciech Jaruzelski favors the latter, pragmatic course. They say he has his sights set on national conciliation based on continued modus vivendi with the Roman Catholic Church, patience in rebuilding the regime's credibility, and persistence with the economic reform.
They see recent developments as part of a calculated tightening up designed to head off anti-reform hard-line charges of excessive tolerance toward former party members and others who still decline to fall in line - or continue active opposition.
It includes not only his recent harsh tone against intellectuals, but also the smoking out of well-known journalists dismissed from influential newspaper posts who found havens in specialist media not normally read by the masses and continued to air critical views.