Like Helen Clark before him, John Key has stepped into the middle of a Maori process and said, 'this far, no further'. But ignore talk of a "gaffe", this is carefully contrived politics

Was this John Key's "Shrek" moment? Almost exactly six years ago, Helen Clark let her tongue run away with her, saying that she would rather pose with an over-wooled merino than with members of the hikoi that was heading to Wellington, protesting over the foreshore and seabed.

The Labour government's approach to the foreshore and seabed was driven by politics – its need to apease Don Brash's "mainstream" Pakeha voters and its belief in collective ownership. My guess is that her flippancy was also politically motivated; if not planned, then guided by a well-trained instinct that the majority would share sympathy for a sheep over veteran Maori protesters.

But she misread the depth of feeling across Maoridom, the determination of those concerned and perhaps hadn't realised quite how the generations-long ties between Maori and Labour had been loosening in recent years. And she saw a new party evolve that has since snatched most of the Maori seats away from Labour's grasp.

In the long-term, the Shrek gag didn't play so well for her.

John Key's gag this week about being dinner had he been supping with Tuhoe rather than Ngati Porou has more than a few similarities. It too stems from his instincts – in this case the carefully honed self-deprecating humour that lies at the heart of his popularity. This is Sunny John, the affable PM.

But it also stems from his efforts to woo that "mainstream" vote. I have no inside knowledge of National's polling, but his decision to step into the middle of the Tuhoe negotiations and start kicking sand in people's faces suggests a few focus groups were making noises about National – or Key in particular – being a little too cosy with the Maori Party.

The poor taste joke at the Ngati Porou dinner may have been a "gaffe" in the eyes of some, but the context created this week hasn't happened by mistake.

Perhaps he was concerned about internal Cabinet tensions about the Tuhoe deal, or more likely he was playing to the masses. But either way he has used Tuhoe for his own political gain.

Just as Clark did before him, Key has stopped Maori in their tracks to appease tht "mainstream". Clark stopped iwi going to court to limit Maori ownership aspirations, Key has stopped Tuhoe's aspirations in much the same way.

The fact that Key has offended just one iwi, and the nature of tribal politics within Maoridom, may contain the political fallout. But in principle Key has done exactly as Clark did – stepping into the path and blocking the way, just as some Maori saw a way forward to greater self-determination.

Each Prime Minister can make a strong case for choosing to act. To take from the Treaty of Waitangi (even though Tuhoe enver signed it), they are holding the kawantanga of the Crown as supreme over the rangatiratanga of iwi. But in each case it is undoubtedly a slap-down to Maori aspirations.

Sure, Key will take a hit for that amongst some Maori, and he risks the simmering upset that Clark sparked. Tuhoe will remember his slight and will fight back. But he will have done his usual cost-benefit analysis and figured that offending some Maori who would never vote for him anyway is less important than reaching out to those in his base worried that he may be giving away too much to Maori.

Which leaves the question of how the Maori Party respond. They are too invested in this government to walk away to scream too loudly. Key, of course, has made sure of that. So they risk looking like captives while he plays politics, safe in the knowledge that he can re-build bridges over the next 18 months.

The Maori Party, therefore, are left to cuddle their tobacco tax rise and indigenous rights declaration closer to their chests, trying to reassure themselves and their supporters that such offence is worth it in the long run, and just part of the rugged game they've chosen to play.

Remember, Labour's intervention in the foreshore and seabed case spawned the Maori Party. Yet when National chooses the same approach, if only to one iwi, all they can do is mumble about putting Tuhoe negotiations at risk.

So the week ends with the Maori Party having lost face and National supporters happily chewing on the bone thrown them by the Prime Minister.

So ignore talk of the PM's gaffe this week. My guess is that he heads into Budget week a perfectly happy man. His worry now will be about the politics of next Thursday, because after all, "it's the economy, stupid".