New Zealand's Prime Minister John Key speaks at a luncheon in Sydney February 7, 2014 file photo. REUTERS/Brendon Thorne/Pool
Key is considered one of the most popular prime ministers in New Zealand's history. He was praised for his stewardship of the NZ$240 billion ($170 billion) economy following the global financial crisis and the two earthquakes around Christchurch.REUTERS/Brendon Thorne/Pool

New Zealand Prime Minister and Leader of the National Party John Key announced his resignation on Monday, a decision that has taken his country by surprise. He held a press conference in Wellington after informing the cabinet of his decision.

"There is no way I could have served out a full fourth term... 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," Key said at the press conference, adding that stepping down was the hardest decision he has had to make.

"Sometimes you've got to make hard decisions to make right decisions," Key, a former foreign exchange dealer who won office for the National Party in 2008, said.

He cited family reasons for his resignation and added that it was the "right time" to leave politics after having been in power for over eight years. He told the media that he had no immediate future plans and that he would stay in Parliament long enough to avoid a by-election for his seat.

Key's resignation will be effective from December 12 and the national MPs will meet on the same day to decide on a new leader.

Key has said that he would vote in favour of Deputy Prime Minister Bill English if the latter decides to put his name forward. English had led the National Party to its worst-ever electoral defeat in 2002, following which he served as a successful finance minister.

Key is considered one of the most popular prime ministers in New Zealand's history. He was praised for his stewardship of the NZ$240 billion ($170 billion) economy following the global financial crisis and the two earthquakes around Christchurch.

Key recently celebrated his 10-year anniversary as leader of the National Party.