Dr. Manmohan Singh, the Prime Minister of India on 17 June 2013 took oath as the member of Rajya Sabha. He was elected to Rajya Sabha for the fifth consecutive term from Assam. In the election, he was the only contestant for the first preference vote seat.
Chairman of Rajya Sabha, Mohammad Hamid Ansari administered the oath to Manmohan Singh in his chamber in the Parliament House.
PART V, of the Constitution of India under Article 99 provides power of Oath or affirmation by members. The Article mentions:
Every member of either House of Parliament shall, before taking his seat, make and subscribe before the President, or some person appointed in that behalf by him, an oath or affirmation according to the form set out for the purpose in the Third Schedule.