In the meantime the PPR engaged in a massive program of rebuilding the country and its industry, in combating and containing the various forms and manifestations of opposition to its rule, but also in manipulating the election preparation process to ensure the party's lasting domination.

The views adhered to and promulgated by its leaders (Maria Koszutska, Adolf Warski, Maksymilian Horwitz, Edward Próchniak) led to the party's difficult relationship with Joseph Stalin already in 1923–24.

In 1935 and 1936, the KPP undertook a formation of a unified worker and peasant front in Poland and was then subjected to further persecutions by the Comintern, which also arbitrarily accused the Polish communists of harboring Trotskyists elements in their ranks.

[8][9] Among the communist groups that became active in Poland after Operation Barbarossa was the Union for Liberating Struggle (Związek Walki Wyzwoleńczej), whose leaders included Marian Spychalski.

Berling, Alfred Lampe, Stefan Jędrychowski, Andrzej Witos and Bolesław Drobner were among the communists and individuals of other political orientations active in the organization, people willing to participate in a communist-dominated undertaking.

Its important members were Chairman Aleksander Zawadzki, Wasilewska, Karol Świerczewski, Jakub Berman, Stanisław Radkiewicz, Roman Zambrowski, Hilary Minc and Marian Spychalski.

Some of them would later form the core of the Stalinist and strictly pro-Soviet (internationalist in outlook) faction of Poland's ruling communists, who worked closely with Bolesław Bierut and were opposed to the national PPR current led by Gomułka.

The PKWN Manifesto was issued, in which the committee claimed its authority in liberated Poland and announced fundamental and wide-ranging reconstruction and systemic changes, most prominently a land reform, to be implemented in the country.

Mikołajczyk advocated compromising with the Soviets for the sake of preserving the country's independence, while Sosnkowski, counting on the outbreak of war between the Allies, rejected making any concessions.

The talks with Bierut, Osóbka-Morawski and Wasilewska did take place, but Mikołajczyk found the communist ideas and demands unacceptable, even though he was offered the job of prime minister in a combined government.

[20][22] In 1944, the lack of Polish-Soviet diplomatic relations and the resultant inability to conduct negotiations forced the Polish leadership to undertake political and military actions in an attempt to create a fait accompli situation in Poland that the Soviets would be compelled to accept.

According to the planned Operation Tempest, the retreating German forces would be attacked by the Home Army, temporary Polish civilian administration would be installed in the liberated areas and its members, representing the government-in-exile, would greet the incoming Soviets as the rightful hosts.

The Home Army capitulated on 2 October, Warsaw was subsequently largely demolished per Adolf Hitler's orders, and the Polish government-in-exile was no longer capable of staging major armed demonstrations in Poland.

President Roosevelt disappointed the Poles by designating the Polish, British and Soviet governments as the proper forum for border discussions, but Prime Minister Mikołajczyk, unable to convince his colleagues of the need for further compromises, resigned on 24 November 1944.

[20] The KRN and the Provisional Government gradually strengthened their position, as the Soviet NKVD facilitated the process by performing large scale arrests of opponents of communist rule.

In the summer of 1944, the First Polish Army established bridgeheads on the Vistula'a left bank south of Warsaw and in August its 1st Armoured Brigade fought the Germans at the Battle of Studzianki.

It fought on the 1st Belorussian Front and during the following month participated in overcoming strongly fortified German defenses at the Pomeranian Wall, losing 6,500 soldiers; in March it took Kolberg.

These postulates and the Soviet demand for Poland's eastern Kresy territories were accepted by the PPR and allied Polish Socialist Party (PPS) leaders, with considerable support from the agrarian movement politicians, who were also opposed to the April Constitution (1935) regime.

As for the practical implementation, a commission representing the three great powers negotiated the issue of the TRJN in Moscow and the talks had been stalled for a long time, until joined by former Prime Minister Mikołajczyk of the government-in-exile.

[26] Operating within the Soviet-controlled international environment, regardless of the results of the upcoming mandated elections, the Polish communists had no intention of giving up political power and made no secret of it.

[26] The PPR invoked the tradition of social struggle in the Second Polish Republic and the party gained support of many politicians of leftist orientation from the peasant and socialist movements, who shared that point of view.

Decisions concerning the Polish–German border were made at the Potsdam Conference, where Stalin lobbied for Poland's maximal extension in the west, arranged for the Polish government delegation to present their point of view and in the end thwarted the long-standing British policy (aimed at keeping some of the lands in question for the future German state).

In Poland, the PPR led the massive "Recovered Territories" propaganda campaign, the Allied-authorized expulsion of ethnic Germans and the repopulation of the region by Poles "repatriated" from the lost Kresy eastern areas.

The exact eastern boundary was determined in the Polish–Soviet treaty signed on 16 August 1945, which finalized the contested issue of Lviv (the city stayed on the Soviet Ukrainian side of the border).

Existence as a social class of ziemiaństwo (large scale land owners) was undercut, while the free market economic system was for the most part still functioning in the country.

[31] Politicians in Poland connected in the past to the Sanation and National Democracy formations did not recognize the new realities and waged a determined campaign against the communist authorities, boycotting decisions of the government, especially the ones having to do with the establishment of administrative and military structures.

[31] The referendum asked three questions: about abolishing the Senate (parliament's upper chamber), future constitutional moderate socialist reforms, and the permanency of Poland's western and northern borders.

Accordingly, the referendum was conducted under considerable pressure (such as heavy military and police presence) and the results were falsified to give the Democratic Bloc a strong majority it wanted.

[33] Because of the deepening division in international politics and the emergence of two mutually hostile blocs, Stalin demanded stricter loyalty in the Soviet sphere; purges of circles and individuals considered ideologically corrupt or otherwise unreliable were pursued.

All this had changed with the establishment of the PZPR: the Six-Year Plan of heavy industrial development was imposed and the building of state socialist system and society commenced in earnest.