John Key was born in 1961. Unusually for an English-speaking PM, he is openly a non-believer. He grew up in a state house (British "council house") in Christchurch, where he gained a degree in accountancy.
He has been MP for Helensville (nothing to do with Helen Clark!) in north Auckland/Akarana. (Yes, another bloody Aucklander). 2002-11. In 2011 he got 74% of the vote.
At the moment there appear to be no threats to his leadership.