Are we approaching a political tipping point?

On their own, the odd golf game, visa waiver or dinner doesn't shake public confidence in a government. Until something happens that pulls the threads together and puts them in a new light... Enter Maurice Williamson...

In his 2000 book, The Tipping Point, Malcolm Gladwell made sense of the way social trends and ideas seem to suddenly take on a life of their own, by comparing them to viruses. The way Hush Puppies became popular again because a few New Yorkers took a fancy to them, for example. All the idea or product or trend needs is a tipping point – "the moment of critical mass, the threshold, the boiling point" where the drip, drip, drip becomes a flood.

Political trends work much the same way and Labour is looking for that point this week. Since John Key first ran for top office in 2008, Labour has been looking to paint the former Wall St man as one of Michael Cullen's "rich pricks". Mike Williams famously went digging into his past and the line was run that a currency trader worth $50m was out of touch and too close to big money and the exclusive elite.

The strategy was a flop due in large part to John Key's character – and persona. As calculating as the Prime Minster can be (and as wealthy and well-connected as he is) there is an authenticity about him and a easy-going manner that has confounded such Opposition attacks.

Until now. Key, apart from arguably too many golf games and a tendency for him to use his popularity to become 'Fundraiser in Chief', remains clear of any taint, but his government is starting to look questionable beyond the beltway. The complaints of "crony capitalism" and too much help for "the big end of town" that used to bounce off the Key-led government are now striking the odd hit.

We're not at tipping point yet, but this past week suggests to me a change in the wind.

The golf games, dinners at Antoines and offers of face time to raise money for the Maori Party all looked a little dubious, but nothing a busy electorate would care too much about. Hey, powerful people do posh things, right? And isn't the economy recovering? The Oravida case was a big dodgy, but really it was too complicated and nuanced for most people to understand.

Maurice Williamson and his phone call to the cops on behalf of a multi-millionaire Chinese businessman though, that people can understand. He rang the top cop in his district and, if the police are to be believed, prompted a review of the investigation into that businessman. It's dirty. They might not see it as a hanging offence on its own, but suddenly it puts all the other dealings in a different light.

Is this simply favours for rich mates? Is this special treatment for the few? And when these golf games, dinners in China and help with immigration are all followed by donations to the National Party, well, people start to take notice.

It's too soon to say, but could Williamson's misdemeanour be the start of a tipping point? That's what Oppposition parties are hoping for and what they will be pressing in parliament this week.

Add in the u-turn on legal highs last week and the general air of competence that surrounds this government is looking less robust. Then add Labour's new monetary policy that a) wasn't bungled and b) earnt mild praise from business leaders and Don Brash, and suddenly there's a new degree of pressure on National's discipline.

I wrote just over a week ago that this past week was going to be crucial for Labour; that it was running out of last chances. Well, it certainly took those words to heart and made the most of its week! Now it needs to do it again. And again.

Think about it through a rugby analogy. It's much easier to keep possession, force penalties and spot the gaps when you aren't under pressure. You have time to play your natural game, you can focus on your own tactics and not be distracted by the opposition. Under pressure, you make mistakes. Just look at Judith Collins' outburst at Katie Bradford yesterday.

Labour has some points from Williamson's resignation (sin binning), but it needs to stay down National's end of the pitch and get more points while Williamson is off the field.

National knows all this and I'm sure the message going round the troops is to double down, get their hands back on the ball and maintain discipline. This is not the time to be giving away easy penalties.

There's every chance National can soak up the pressure and fight back; this government has done it before and – to switch to a cricket analogy – it's got a power play coming up in the form of the Budget. Focus and opportunity swings back its way soon.

Enough of the sport metaphors. Williamson's departure of course makes Collins' survival all the more crucial for National. To lose one minister shows discipline; to lose two suggests incompetence. Key, however, must be sick of defending her and the personal attack on Bradford might have been the final straw required for a stand-down in any normal week. But this hasn't been a normal week. So Collins' incredible luck holds.

Her problem though is in part of the Prime Minister's making. When it became clear that the Oravida dinner wasn't just a drive-by on the way to the airport and there was more to it than Collins had previously revealed to him, he had every reason to stand her down. He chose instead to stand by her and may well now be regretting that choice, because the "perception of a conflict of interest" that the Cabinet Office referred to is sufficient to keep Opposition parties on her tail. What's more, the fact he publically said she was on a final warning was a mistake – it put a target on her back and gave the left every incentive to keep hunting for the single nugget that will push her over the edge. Another potential tipping point.

So can National push back from the edge? Or can Labour and its allies finally make the charge of crony capitalism stick this time? With the Budget just two weeks away, they have a small window in which to exploit that opportunity. On the other side, it'll be interesting to see whether National just clings on for a week or if it can find some offence to use as a form or defence. Remember, the election is still National's to lose.

So can National contain the epidemic or can Labour make it contagious? We should know by the end of the month.