Andrew Little on Prime Minister John Key's resignation: He 'served New Zealand well'

Leader of the Opposition Andrew Little has paid tribute to outgoing Prime Minister John Key, saying he has "served New Zealand well".

Speaking at a press conference this afternoon, the Labour leader would not comment on whether Key's shock resignation had made his job easier.

But Little was clearly buoyed by the imminent departure of his popular rival, repeatedly saying that he and Labour were "ready to go" and that he was ready to debate Key's successor.

John Key has served New Zealand generously and with dedication. I wish him and his family the best for the future.

— Andrew Little (@AndrewLittleMP) December 5, 2016

But first, Little said he wanted to recognise Key's leadership, in particular through the global financial crisis and a series of natural disasters.

"The role of Prime Minister is a tough gig at any time," Little told reporters.

"It is hugely challenging, not only in the role but for family members.

"I want to pay tribute to the contribution that John Key has made to New Zealand in his time as Prime Minister."

He added: "Today is a day to say to him about his service, thank you for serving New Zealand and for New Zealand well.

"There are still challenges, and we need to rise to those challenges as a country."

Little said he did not have a view on the next prime minister and the decision was "entirely up to National". He would not name a preferred successor to Key.

He also would not be drawn on whether an early election should be called, allowing voters to choose the next prime minister instead of the National caucus.