The rift between the two sides [the 3 December events, (the "Dekembriana")]
The demonstration organised by the KKE leadership for 3 December 1944 in Athens ended in bloodshed and constituted the beginning of a widespread conflict between left-wing organisations and the forces loyal to the Greek government. In this confrontation the British troops took an active interest and part. This involvement was the first major indication that the British government was determined to support the Greek administration against the threat of a communist uprising and of left-wing domination in Greece.
The last days of 1944 were marked by intense political activity, especially due to the decision of the British government to mediate between the two opposing sides for a compromise agreement. The Prime Minister George Papandreou submitted his resignation right after the incidents of 3 December but he received the full backing of Churchill and thus decided to stay in his position.
However, the British Prime Minister realised the danger that Greece could become the battlefield not only of a domestic, but also of an international confrontation between pro-western and communist forces. He, therefore, decided to intervene personally in the mounting crisis in Greece. For this purpose, he visited the country in 24 December 1944, accompanied by his Foreign Minister, Eden. During this official visit the British side exercised strong pressure on both sides for the resolution of the extremely tense situation which followed the 3 December events.
The mere presence of Churchill in the country speeded up the process.
Papandreou was replaced by the traditional politician Nikolaos Plastiras
as Prime Minister. This move was intended to appease the KKE and ELAS
leaderships which, from the first moment, had made their opposition to
Papandreou's policy clear. Besides, KKE had in numerous cases demanded
Papandreou's removal from office as a precondition for the reopening of
negotiations with the government and the improvement of the domestic situation.
Indeed, Plastiras' appointment as Prime Minister improved the political atmosphere in the country and made the KKE leadership reassess its previous policy of non-cooperation which it had adopted since November 1944.