For much of the period that he was in charge of the National Party, Hamilton was regarded a conscientious but lack-lustre leader. Although National's performance had improved in the election by winning an additional six electorates, Labour was still in government and there were discussions about replacing Hamilton. Hargest, who had retained his Awarua seat for National in the election, was one of two contenders for the party leadership (the other was Keith Holyoake, but he had lost his electorate). With the outbreak of the Second World War, Hargest immediately volunteered for active service. The National Party leadership eventually went to Sidney Holland in November 1940; there was a view that this was a temporary situation that could be reassessed once Holyoake or Hargest returned to Parliament. Hargest remained a member of parliament during his time on active service and in the , he was the sole candidate in the Awarua electorate whilst an internee in Switzerland; he was thus returned unopposed.