Holland was elected to parliament in , and became the second Leader of the National Party, and Leader of the Opposition, in 1940. He served briefly (1942) in a war cabinet but thereafter attacked the Labour government for its interventionist economic policies. Holland led the National Party to its first election victory in . His National government implemented moderate economic reforms, dismantling many state controls. Holland's government also undertook constitutional change in 1950, by abolishing the Legislative Council, the upper house of parliament, on the grounds that it was ineffectual.