Reshuffles for National and Labour ensure political frenzy right up to Christmas break

Bill English arrives at the Beehive yesterday ahead of today's swearing-in. Photo / Marty Melville

This week was meant to be a quiet end to the Parliament year but instead a new Prime Minister will be sworn in and reshuffles will take place in both Labour and National before MPs slink off for the summer break.

Bill English will be sworn in by the Governor-General as Prime Minister today with Paula Bennett as his deputy after a special National caucus meeting yesterday morning to anoint the pair as National Party leader and deputy.

The pair met at Parliament yesterday for initial talks while John Key was also at Parliament with wife Bronagh to pack up the rest of his office - and probably give his successor a few handover notes.

English has already said Steven Joyce will be his finance spokesman and is expected to announce his full new Cabinet before Christmas. English, Bennett and Joyce all declined interviews yesterday.

Labour leader Andrew Little will also do a reshuffle because of the looming departures of David Shearer and David Cunliffe.

Little said he expected that would come later this week.

"It's not big, it's not starting from a blank page. It's taking the changes we know and accommodating those."

Shearer has the foreign affairs and defence portfolios while Cunliffe has portfolios including science and technology and land information.

Little said the departure of Key did not change the issues New Zealand faced, such as housing.

Shearer is expected to be formally announced as the head of the UN's mission in war-torn South Sudan on Tuesday and will resign almost immediately. His job starts at the end of January.

That will spark a byelection in his Mt Albert seat unless English opts for an early election, which is unlikely.

Labour's candidate is likely to be MP Jacinda Ardern, who now lives in the electorate but was initially aiming for a third tilt at winning the marginal Auckland Central seat.

She said yesterday she was yet to make up her mind. If Ardern won Mt Albert, Labour could bring in another List MP - Little is understood to be keen to get Raymond Huo back into Parliament before the election to give Labour Chinese representation.

Labour's general secretary Andrew Kirton said the party will reopen nominations in the seat this week and chose a candidate by the end of January.