Meanwhile, he served as political adviser then deputy head of the Department for International Relations of the Central Leadership of the Hungarian Working People's Party (MDP) from 1949 to 1955.

[1] While also being a state security officer,[1] Hollai functioned as Hungary's Deputy Representative to the United Nations from 1955 to 1960,[2] residing in New York City.

Returning home, he was head of foreign relations for the Central Committee of the Hungarian Socialist Workers' Party (MSZMP) from 1960 to 1963.

Due to his great success in this role and popularity among his peers in international diplomatic circles due to his charismatic intelligence he was seen as a threat to the rigid communists in the Hungarian hierarchy and forced to return as ambassador to his earlier post in Greece and Cyprus in 1984.

[1] However, he had been an active member of the Council of Presidents of the General Assembly, the body informally advising the Secretary-General of the United Nations.