After the coup on 1 November 1963, in which Diệm and Nhu were killed the following day, Thơ was appointed Prime Minister by Minh's military junta five days later, on 6 November 1963. He was the leading civilian in the provisional government overseen by the Military Revolutionary Council (MRC). Minh had earlier promised U.S. officials that the civilians would be above the generals in the hierarchy. In addition, he was minister for finance and the economy. Thơ's appointment was not universally popular, with some leading figures privately lobbying for a clean break from the Diệm era.