[citation needed] He was the last prime minister from the Rana family, which had controlled Nepal for more than a century and reduced the monarchy to a figurehead.

Tribhuvan wanted to establish a stronger monarchy and some democracy, which Mohan Shumsher opposed.

In 1950, Mohan Shumsher's policies against the monarchy forced Tribhuvan and his son Mahendra to flee to India with the help of the Indian Residency and the Indian government, which led Mohan Shumsher to proclaim Mahendra's three-year-old son Gyanendra the king of Nepal.

By the end of 1951, the King and his allies in Congress had triumphed, and Mohan Shumsher and the rest of the Rana family lost power.

The Ranas were removed from all the hereditary offices and privileges conferred by King Surendra Bikram Shah on Jung Bahadur even though Mohan Shumsher still held the office of the prime minister, several demonstrations by Rana supporters in an attempt to reestablish their rule and the opposition of the monarchy and Congress forced him to resign from his position.