Popular New Zealand Prime Minister John Key calls it quits

Wellington, New Zealand | AFP |.Popular New Zealand Prime Minister John Key announced his shock resignation Monday, saying he was never a career politician and it was the right time to go after eight years in the job.

The former Merrill Lynch currency trader called it "the hardest decision I've ever made", with no plans on what to do next other than spend more time with his family.

"Being leader of both the party and the country has been an incredible experience," he told a regular weekly news conference.

"But despite the amazing career I have had in politics, I have never seen myself as a career politician."

Key recently marked his eighth anniversary as prime minister and 10th year as leader of the centre-right National Party, which is set to meet next week to elect his successor.

His deputy Bill English, who led the party to its worst result in the 2002 election, is widely seen as favourite to take over and was endorsed by Key, although he did not immediately confirm he wanted the role.

"Certainly, I wouldn't stand if there wasn't strong caucus support for me standing," he said, adding that since the 2002 flop he had received "a masterclass every day from John Key about how to do politics".

As discussion about Key's decision to walk away swirled around social media, the down-to-earth politician -- once voted the leader most New Zealanders would love to have a beer with -- insisted he was "not the kind of guy that has to hang on to power for power's sake".