At last, Phil Goff has something to smile about.

Exactly why the Labour leader is smiling might not seem immediately obvious given that National's Jami-Lee Ross won Saturday's Botany byelection in a canter, securing almost double the number of votes of his Labour counterpart.

The answer is that everything is relative in politics. Labour did better than it hoped. National did not fare as well as it would have expected.

Of some worry to National will be the bleeding of its votes to the New Citizen Party, which picked up 10.5 per cent of the total candidate vote and pushed Act into fourth place.

If replicated in electorates across Auckland with large populations of New Zealand Chinese, such splintering of centre-right support could see large piles of wasted votes if the new party fails to reach the 5 per cent threshold.

That could diminish the centre-right's representation in Parliament by one or two seats - seats which may well be crucial for National to retain power.

It is questionable, however, how meaningful conclusions drawn from a byelection can be, let alone one as stifled by circumstances as this one.

Still, the debut of the New Citizen Party and National's failure to lift its vote would seem to pour cold water on the possibility of National securing a majority alone.

The complicating factor is Saturday's abysmally low turnout. However, the non-vote would more likely be weighted in Labour's favour.

The 36.6 per cent turnout - half that of a general election - meant both major parties got fewer votes than at the 2008 election. Labour's vote proved more robust. National's vote halved from more than 17,000 to just over 8000. In comparison, Labour's vote fell, but far less dramatically - from around 6500 to just over 4000.

The net result is: Labour increased its share of the candidate vote in the seat from 21 per cent in 2008 to 28 per cent on Saturday.

Moreover, it did so in the face of a number of handicaps - notably the party's candidate, Michael Wood, committing one of politics' great sins early on by saying he would not win the seat.

At a minimum, the result boils down to a psychological victory for Labour, one which Goff wasted no time milking by staging a lunch-time photo-opportunity yesterday at a cafe in Botany town centre.

His claim the result is a "significant swing" against the Government ignores National having won about the same share of the vote as it did in 2008.

Moreover, although such comparisons are questionable, there is not a big difference between Labour's party vote in the seat in 2008 and its candidate vote this time.

As for Act, Rodney Hide may not know whether to laugh or cry. The party's candidate, Lyn Murphy, got 671 votes.

That amounts to less than 5 per cent of the vote in the kind of seat where Act should be hitting double figures.

However, Act's party vote in the seat was less than 5 per cent in 2008. The byelection result suggests that while Act may still be down, the party is definitely not out.

The party is holding its annual conference next weekend. It does so with a fig-leaf of electoral respectability - but nothing more.