When Prime Minister Harold Holt disappeared in December 1967, presumed to have drowned, Hasluck was determined that the Treasurer, William McMahon, of whom he had a very low opinion, should not become prime minister. Although he had no great ambitions for himself, Hasluck put his name forward mainly to provide an alternative to McMahon. In the event, McMahon did not stand, as the interim prime minister John McEwen had advised his Country Party would not serve in any government headed by McMahon. The choice was between Hasluck, John Gorton, Billy Snedden and Les Bury, although the latter two were never considered serious contenders. Many Liberal MPs saw Hasluck as too old at 64, too conservative, and insufficiently telegenic to compete with Labor leader Gough Whitlam. Accordingly, they chose the younger and more aggressive Gorton.