During the British colonial rule in India, Sikkim had an ambiguous status, as an Indian princely state or as an Indian protectorate. Prior to Indian independence, Jawaharlal Nehru, acting as the leader of Executive Council, agreed that Sikkim would not be treated as an Indian state. Between 1947 and 1950, Sikkim enjoyed "de facto" independence. However, the Indian independence spurred popular political movements in Sikkim and the ruler Chogyal came under pressure. He requested Indian help to quell the uprising, which was offered. Subsequently, in 1950, India signed a treaty with Sikkim bringing it under its suzerainty, and controlling its external affairs, defence, diplomacy and communications. A state council was established in 1955 to allow for constitutional government under the Sikkimese monarch. Meanwhile, trouble was brewing in the state after the Sikkim National Congress demanded fresh elections and greater representation for the Nepalese. in the 1967 Nathu La and Cho La clashes, Chinese border attacks were repulsed. In 1973, riots in front of the palace led to a formal request for protection from India. The Chogyal was proving to be extremely unpopular with the people. In 1975, the "Kazi" (prime minister) appealed to the Indian Parliament for a change in Sikkim's status so that it could become a state of India. In April, the Indian Army moved into Sikkim, seizing the city of Gangtok and disarming the Palace Guards. A referendum was held in which 97.5% of the voting people (59% of the people entitled to vote) voted to join the Indian Union. A few weeks later, on May 16, 1975, Sikkim officially became the 22nd state of the Indian Union and the monarchy was abolished.