Millions of Polish workers took part today in a one-hour strike organized by the independent trade union federation Solidarity to protest the communist government's economic policies and alleged harassment of union activists.

Solidarity officials said the nationwide strike, the biggest single action to be staged by the union in seven months, was a dramatic success. Citing reports from factories, mines, and public transportation companies throughout Poland, the union's information agency here said the protest had attracted between 90 and 100 percent support.

These figures were disputed by Communist Party officials. They did concede, however, that many rank-and-file party members had joined the strike in defiance of instructions from the party leadership.

The strike was denounced as a political provocation by the new Communist Party chief, Gen. Wojciech Jaruzelski, at a meeting of the policy-making Central Committee. The Army newspaper, Zolnierz Wolnosci, described it as "blackmail...designed to push Poland into crises reminiscent of Hungary in 1956 and Czechoslovakia in 1968," when reform movements were crushed by Soviet intervention.

Western analysts saw the strike as an impressive demonstration of public support for Solidarity despite Poland's mounting economic difficulties and political tensions. It appeared to disprove suggestions that the union's standing in the country had been seriously undermined as a result of widespread food shortages.

The timing of the strike clearly complicated Jaruzelski's efforts to reshape the government and party leadership. Addressing the Central Committee, he indicated that major personnel changes had been postponed for the time being.

Using a military metaphor, he said: "Today we find ourselves under extremely heavy fire from the opponent -- and one does not carry out a broad maneuver while under fire."

A promised shake-up in the party Politburo was confined to the election of the deputy defense minister and Army chief of staff, Gen. Florian Siwicki, a candidate member of the 15-member body. The move was seen as yet another in the increasing involvement of the Army in public life, a trend begun by Jaruzelski's appointment as premier in February.

The Central Committee decided that in view of the gravity of the crisis, Jaruzelski would be allowed to combine the posts of party first secretary, premier and defense minister. Such an accumulation had been excluded by the party congress in July and it had earlier been thought that a new premier would be appointed.

Jaruzelski said the appointment of soldiers to party and government positions reflected "the needs of the moment." He added: "They will go once they have done their duty and the need for their presence ceases."

Another party leader, Politburo member, Kazimierz Barcikowski, raised the prospect of new but still undefined action against Solidarity should the union not halt the industrial unrest now sweeping the country. He said the national legislature, the Sejm, would be taking action to limit strikes at its meeting on Friday.

He added: "Should Solidarity's conduct remain unchanged, other far-reaching decisions designed to protect the vital interests of the nation and state will become indispensable."

At a meeting last week, the Central Committee called on the Sejm to pass a law temporarily banning strikes. But an outright ban has been opposed by the small Democratic Party, the Communist Party's junior coalition partner, and it is not clear whether it will be accepted in its original form.

In normal times, the Democratic Party's stand would have little significance, given the solid Communist majority in the Sejm. But Jaruzelski would like to broaden the government's support by appointing more non-Communist Party ministers and is therefore obliged to pay more attention than usual to his would-be allies.

Today's nationwide strike began at noon with the sounding of factory sirens all over Poland. Health services, radio and television and electric plants were exempted from the protest, but workers showed their support by wearing red-and-white armbands.

In schools, teachers staged a symbolic protest by suspending normal classes and explaining to pupils the reasons for the strike. Solidarity has demanded the establishment of an independent socioeconomic council to monitor the government's economic policies and called for a halt to the prosecution of union activists and closure of uncensored union publications.

In calling for a nationwide strike, Solidarity leaders also appealed for an end to uncoordinated local protests. But there appeared to be little immediate prospect of the unrest subsiding, and the government information agency Interpress reported last night that 36 of Poland's 49 provinces were affected by strikes or other protests.

Addressing strikers at a lightbulb factory in Warsaw, Solidarity leader Lech Walesa said he hoped the strike would be the last of its kind. In the future, he said, the union should organize "active" strikes by temporarily taking over the role of management and distributing goods directly.

Meanwhile, a fresh local dispute flared up at a mine in the southwestern industrial province of Silesia. Miners at the Sosnowiec mine went on strike after a mysterious incident in which vials of blister gas were thrown into a union rally from a passing car.