MNR was instituted as the sole legal political party in the country on July 20, 1964, according to the Law No.

[5] In August 1964, a founding congress of the Youth of the National Movement of the Revolution (JMNR) was held.

A law was passed on June 22, 1966, which transformed the Congolese Armed Forces into the National People's Army (APN).

The lieutenant Marien Ngouabi, later the president of the country, became the APN representative in the MNR Central Committee.

[6] In the same year 1966 a political dispute erupted between the President Alphonse Massamba-Débat and the leftwing of the MNR.