Andrew Little is wise to have ignored the pressure that was coming even from Labour quarters for him to pull his party's candidate from the Northland byelection in order to avoid splitting the Opposition party vote and instead boost Winston Peters' chances of winning the seat.
It is now too late to withdraw Willow-Jean Prime's nomination as Labour's candidate. Barring a candidate's death or sudden incapacity, a nomination cannot be pulled after noon on nomination day - which was yesterday.
Little may not have completely ruled out urging Labour-leaning voters to cast their vote in Peters' favour. Byelections can be unpredictable affairs. So it is sensible for Opposition parties not to foreclose on their options too early in the campaign.
But Opposition politicians also have to be realistic.
It would require everything to go spectacularly right for Peters and everything to go drastically wrong for John Key in the three or so weeks until polling day on March 28 for Peters to pull off a very unlikely victory.
Peters cannot win unless huge numbers of National voters stay at home.
Northland, however, is a record-setter when it comes to signed-up National Party members.
There will be no shortage of volunteers to get out the National vote.
Winning a safe government seat in a byelection requires there to be huge antipathy towards that government.
Northland has its problems. But it will take some truly inspired campaigning by Peters to turn that into a backlash against National.
To mangle an old saying, it is not so much the winning of the byelection which counts.
It is how those Opposition parties play the campaign to enhance their appeal beyond the boundaries of the Northland electorate.
One question lingers.
Since becoming Labour's leader late last year Little has devoted considerable attention to raising his own profile while taking the first steps in rebuilding Labour and restoring its historic status as the dominant political force on the centre-left.
Part of that mission requires that the Greens be brought down a peg or two - something that party has already achieved through the resignation as co-leader of its best weapon, Russel Norman.
Labour also needs to recover what was a pretty conservative and predominantly male chunk of its vote which lost patience with the party's advocacy of whatever was deemed to be politically correct and deserted to New Zealand First.
So why on earth would Little want to halt the growing momentum behind his leadership and instead allow Peters to make all the running for the next three or so weeks.
That Little is already putting the squeeze on New Zealand First can be discerned from Peters' surprise decision to stand in the seat.
As the Prime Minister has observed, that decision reflects Peters' worry that he is losing his relevancy.
The danger for Peters is that the result of the byelection will only confirm that impression.