Tsirimokos got involved in politics from a young age and was first elected to parliament in 1936 on the Liberal Party's ticket.

During the Axis Occupation of Greece, he co-founded a small leftist party, the Union of People's Democracy (ELD).

However he resigned from that position on 2 December 1944 alongside 3 other left-wing cabinet members after pressure from the British Government.

During the period of the "Apostasia" in the summer of 1965, Tsirimokos was chosen by King Constantine II to form a government.

[3] He failed to gain a vote of confidence, and was succeeded by Stefanos Stefanopoulos, in whose government he retained ministerial posts.