New Zealand Prime Minister John Key to resign

New Zealand Prime Minister John Key has announced he is resigning after more than eight years as leader.

In the unexpected announcement on Monday, Mr Key said it was the "right time" to leave politics, citing family reasons for his departure.

He said he had no immediate future plans, but told reporters he would stay in parliament long enough to avoid a by-election for his seat.

"There is no way I could have served out a full fourth term," Mr Key said at his weekly press conference in Wellington.

"I think in reality if I served six months or a full year, I would have inevitably had to look down the barrel of a camera and say 'I will serve a full three years'. I would therefore have mislead the public and that is not the way of operating."

A former foreign exchange dealer who worked at firms including Merrill Lynch, Mr Key won office for the National Party in 2008, ending the nine-year rule of Labour's Helen Clark.

He won praise with his stewardship of the NZ$240 billion (£134 billion) economy in the aftermath of the global financial crisis and two devastating earthquakes around Christchurch.

The National Party caucus will hold a meeting on December 12 to decide the new party leader and prime minister.

Mr Key said he would vote for his deputy and finance minister Bill English to take over.