His National government implemented economic reforms, dismantling many state controls. In 1951, the National government signed the ANZUS defence agreement with Australia and the United States. The National government also undertook constitutional change in 1950, by abolishing the Legislative Council, the upper house of parliament, on the grounds that it was ineffectual. Consequently New Zealand has since had a unicameral parliament.
In 1954, Holland, having confronted striking dockers and coal miners intent on what he called "industrial anarchy", called a snap election and was re-elected Prime Minister.
Following ill health in 1957, Holland stepped down as Prime Minister to be replaced by Keith Holyoake.