Members of the independent Solidarity trade union today replied to the Soviet Bloc's latest propaganda campaign by inviting a delegation of Moscow car workers to come and see for themselves what is happening in Poland.

The invitation followed a series of clearly officially inspired rallies in the Soviet Bloc condemning the alleged threat of "counterrevolution" in Poland. The Solidarity branch at the Warsaw Transportation Equipment Factory said in its letter that Polish and Soviet workers should be able to understand each other since they face similar problems.

The letter, published by Solidarity today, was in reply to a message sent to Polish workers last weekend by workers at the Zil automobile plant in Moscow attacking Solidarity's recent congress. Since then, similar messages have been pouring in from other Eastern European countries, including Bulgaria and Czechoslovakia, and have been reprinted in the official Polish press.

Whatever Moscow's intentions, the campaign appears to have done little to dampen the militancy of Polish workers. Nor, in the view of most observers here, is there much prospect of postponement or cancellation of the second stage of Solidarity's national congress, set to begin Sept. 26.

Most Polish and Western analysts here say the only way to block the congress would be massive repression. Despite hardening of attitudes on both sides, this remains unlikely. The Polish authorities appear to be playing a waiting game in the hope that public opinion will turn away from Solidarity as the country's economic crisis deepens.

A government task force has underlined the problems ahead by warning of "total economic collapse" this winter unless the decline in coal production is dramatically reversed. The group, headed by Vice Premier Janusz Obodowski, predicted that the shortfall of coal could lead to the shutdown of a considerable portion of Polish industry and big cuts in electrical power.

The report said that total coal output this year would probably be 4.4 million tons short of a scaled-down, 185-million-ton target for this year. Traditionally Poland is one of the world's leading coal exporters, and, for the past two years, it has averaged an annual output of around 220 million tons.

In recent weeks, miners have put in voluntary overtime on Saturdays but according to government figures this has not been enough to avert the threat to industry. The report blamed the introduction of a five-day week for the sharp drop in coal production, Poland's principal source of foreign exchange.

In what could have been seen as a conciliatory move, a Warsaw court today ordered the provisional release of three dissidents accused of conspiring to overthrow the state. But the Supreme Court, at the request of the state prosecutor, overruled the lower court's decision and ordered them held pending trial.

The issue of political prisoners has been a major issue between Communist authorities and Solidarity although, over the past few weeks, it has been overshadowed by union demands for self-management in industry and access to the mass media.

An appeal for conciliation has come from Poland's Roman Catholic primate, Archbishop Jozef Glemp, who was installed in his new position yesterday in a ceremony in the ancient cathedral town of Gniezno.

Glemp said the typical Pole was tired of the crisis, "irritated by standing in lines and depressed in his work since sometimes there is a lack of raw materials . . . . When he comes home he puts the TV set on and, when all he hears is accusations, recrimination, shouts, he switches it off again, isolating himself from the outside world."

In their letter to the Zil plant, the Warsaw workers said the Polish political situation had been misunderstood in the Soviet Union since workers had to rely on reports in the official news media.

They proposed a meeting, saying: "We think that workers of all countries have a common language . . . . Let's talk, discuss, and explain everything to each other."