John Key hopes to be sworn in as New Zealand’s prime minister next week after his centre-right National party won an emphatic victory at the weekend election that ended the nine-year reign of Helen Clark’s Labour party.

Mr Key, a 47-year-old former banker who quit his job at Merrill Lynch in New York six years ago to enter politics, was swept to power on the promise of a better future for New Zealand, which sank into recession at the start of 2008 and is suffering from rising unemployment.