Clark resignation triggers by-election
Helen Clark's confirmation as the head of the United Nations Development Programme will force a by-election in the Mount Albert electorate with speculation it will be held in June.
Miss Clark's spokesman did not know when she would formally resign from Parliament, but it has been reported she will take up her new job within three weeks.
Prime Minister John Key's spokeswoman said no date has yet been set for the by-election.
By-elections have become reasonably rare under the MMP system and this one will be keenly fought.
Miss Clark had a personal majority in the seat of 10,350, but Labour beat only National by 2426 party votes in the electorate in the 2008 election.
The gap between those who voted for left parties in the electorate compared to those on the right of spectrum was slightly larger with the left around 5000 ahead.
However, National is well ahead in the nationwide polls and would fancy its chances of taking the seat, long regarded as a Labour stronghold.
Labour list MP Phil Twyford has been identified as a front-runner for his party, but nominations are bound to come from outside Parliament as well.
Some media have speculated that Labour is developing a strategy to prevent former MP Judith Tizard returning to Parliament.
The reports said Ms Tizard was considered "old guard" and past her use-by date.
Labour's problem is that former finance minister Michael Cullen is also planning to retire, possibly before Miss Clark resigns.
Dr Cullen is a list MP and would be replaced by Damien O'Connor, the next candidate on Labour's list.
If Mr Twyford then contested a by-election and won the Mt Albert seat he would cease to be a list MP and would be replaced by Ms Tizard.
But if an outsider was chosen and won the seat, Mr Twyford would stay as a list MP and there would not be a slot for Ms Tizard to take.
Labour leader Phil Goff has described the speculation as resembling a "witch-hunt" and said the candidate would be selected by the usual process.
Labour candidates are elected by delegates partly selected by the electorate membership at a meeting and partly from the central party.
In the past there have been fierce fights between local members and the party leadership over candidates.
National might seek a high profile candidate to try to win the seat.
Ravi Kumar Musuku stood for National in 2008 and gained 9800 votes compared to Miss Clark's 20,100.
A major local issue is the construction of Waterview motorway which partly runs through the electorate.
Labour had planned a multi-billion dollar tunnel, but National has been sceptical about the cost.
However the alternative would mean the destruction of hundreds of houses and greenbelt land, finding an alternative route, or no road being built at all leaving a missing link in the road network.
- NZPA
Former New Zealand Prime Minister Helen Clark has been appointed as head of the United Nations Development Program.

The appointment follows a unanimous vote by the UN General Assembly yesterday.  Clark will take up the role by April 20, replacing current UNDP Administrator Kemal Dervis.
Helen Clark.
Clark is reportedly eager for the role, comparing it to winning her first election and becoming Prime Minister.  "I guess this is another of those moments," she said.  

The UNDP gives training and advice to developing countries to spur global development and to help them meet the Millennium Development Goals.  It has offices in 166 countries and an annual budget of around US$5 billion. Its Administrator is the third highest ranking member of the United Nations after the United Nations Secretary-General and Deputy Secretary-General.  

Clark has a long political career, having been first elected to Parliament in 1981.  She was New Zealand's first elected woman Prime Minister, serving for three terms between 1999 and 2008.  She became leader of the social-democratic New Zealand Labour Party in 1993, and led it until her defeat in the 2008 general election.  

She has previously held a number of Cabinet portfolios, including Health, Housing, Conservation, and Arts, Culture and Heritage.  In January 2008 Clark won the United Nations Environment Programme Champions of the Earth award in recognition of her government’s promotion of sustainability initiatives.  In January 2009 she was recognised by the ''New Zealand Herald'' as the Greatest Living New Zealander.

Clark's appointment is expected to lead to a by-election in her Mt Albert electorate.