The first partial sale is schedule for the third quarter of 2012, so before 30 September. Labour and the Greens will hope the petition is certified before that sale occurs, as it will allow them to call for the sale to be suspended until after the referendum is held.
They will of course be ignoring their own very recent history, when in August 2009 a referendum saw 87% of those who voted, vote that a smack by a parent for correctional purposes should not be a criminal offence. By coincidence a bill was drawn from the ballot the following week which would have amended the law to do exactly that. Labour and the Greens joined all the other parliamentary parties (except ACT) in voting the bill down.
The Government will then decide on the timing of the referendum, so long as it is within the next 12 months. They will want the turn out to be as low as possible, so that it has a reduced political impact. Hence they could decide to schedule the postal referendum very quickly, say in December. Most people in December are busy doing other things, plus that would get the referendum (which would no doubt vote against the partial sales) out of the way.
The other option for the referendum is that the Government sets it as late as possible, so mid to late 2013. By then it is likely three of the four sales would have occurred, and the referendum would look even more pointless than it is.
After the referendum, there will of course be another election in 2014. Some on the left are convinced that Labour will win the 2014 election due to this issue. In fact senior Labour MP Trevor Mallard went so far as to effectively boast that Labour would win in 2014, 2017 and 2020. I am unsure such confidence, or even arrogance, is entirely warranted.
First there is the reality that National got an unprecedented almost 48% of the vote in 2011, despite having declared their policy 10 months before the election. They got a higher share of the vote than Labour got in 1999, 2002 and 2005 while Labour got their lowest vote in 100 or so years. This indicates that while opponents of the Government detest asset sales, so called swinging voters are not so passionate. By this I do not mean that they support asset sales, even partial ones. It seems pretty clear most New Zealanders do not (just as most New Zealanders think parental smacking for correctional purposes should be legal). But that does not mean, they will determine their vote on this one issue - 2011 shows this was the case.
But there is a further salient point. It is likely that by the time of the 2014 election, the four partial sales will have occurred. It is also likely that National in 2014 will say that there will be no further sales (total or partial) if they are re-elected. Having kept their word in 2008 and in 2011 on keeping to their pre-election commitments on asset sales, this may remove the issue as a salient one (unless Labour promised to buy the shares back). Voters are likely to be more focused on the policies on offer going forward, plus the general state of the economy and public services, than on looking backwards.
This doesn't mean there may not be a political impact from the partial sales. I suspect there will be some - if nothing else, it motivates the Government's opponents to campaign with more vigour. But it is a foolish person who claims 30 months ahead of the election that they have won, let alone the results of the two elections after that.