After the military coup of 1960, once again he was elected and served as Kocaeli representative in the parliament, and this time as head of the CHP group.

In Turkey, after a spree of political violence, and the coup by memorandum, the army forced the resignation of prime minister Süleyman Demirel on 12 March 1971.

Nihat Erim, while still at the university, was advised to withdraw from his post in the Republican People's Party (CHP) by the National Security Council, which was then heavily influenced by the military.

[4] One of the actions in regards of the Kurdish question during Erim's prime ministry was the closing down of the Workers Party of Turkey (Turkish: Türkiye İşçi Partisi, TİP) for its recognition of the Kurds as a distinct ethnicity.

A change in the constitution brought together a witch hunt for leftists, reaching its peak after the abduction and killing of the Israeli ambassador Efraim Elrom in May 1971.

Radical leftist Turkish militant group Dev Sol (Revolutionary Left) claimed responsibility for the attack.

The motive behind the assassination is thought to be related to the approval by the parliament of the execution of three leftist militants, one being Deniz Gezmiş, during his service as prime minister.

Erim's assassination was part of the wave of political violence in Turkey in the late 1970s between left-wing Marxist and right-wing ultranationalist groups.