Far be it that a British immigrant of Anglo-Saxon lineage who has never got around to taking out New Zealand citizenship should lecture a Maori Party MP on the dos and don'ts of politics.

But Hone Harawira has become a right (or should that be left) pain in the butt. The honourable member for Te Tai Tokerau may be a diligent and hard-working local MP helping his constituents solve their problems. Let others be the judge of that.

At the level of national politics, however, he is fast turning into a complete waste of political space.

Harawira's latest missive on the foreshore and seabed was about as constructive as building sand castles below the mean high water mark - a matter mentioned in a question in Parliament on Wednesday from new Act MP Hilary Calvert to Attorney-General Chris Finlayson.

Offering her an instruction manual pulled off the internet, Finlayson told her it was not advisable to build sand castles on the wet part of the beach.

Someone in the Maori Party should offer Harawira instruction on how to make a contribution beyond the banal.

The parliamentary bad-boy act was fun for a while - especially when he went walkabout in Australia from one of those rather pointless parliamentary junkets. But the maverick behaviour has become tiresome.

It's time to knuckle down, Hone. Go look at your colleague, Te Ururoa Flavell, as an example of someone who quietly does the hard yards and is mightily respected for it.

Returning from a "first nations" pow-wow in Canada, Harawira's latest contribution was to urge his party to rip up its support agreement with National and walk away from backing the minority Government if it buckled to Act's demands and inserted a clause in the Marine Coastal (Takutai Moana) Bill to make it explicit that holders of Maori customary title cannot charge for access to the beach.

Harawira is perfectly entitled to raise his objection to such a clause, just as Act has every right to try to usurp Winston Peters' territory while the NZ First leader lacks a parliamentary platform to defend it.

It is understandable that Harawira should be angry at the implied slur cast on Maori by National's insertion of such an amendment.

Though others will no doubt take exception, it is possible to ignore Harawira's description of Rodney Hide as "a little fat redneck".

The constant name-calling and insults coming from Harawira's direction should be seen for what they are - attention-seeking.

What is inexcusable is the daft politics. It needs to be repeated that Maori will not get a better deal on the foreshore and seabed than that thrashed out under Finlayson's watch.

And the other Maori Party's MPs - especially Tariana Turia - know it.

As a top-flight lawyer, the Attorney-General obviously sympathises with Maori over the alienation of their property rights.

He has been straight up and down about the consequences of his legislation in terms of the development rights which will be accorded iwi who get customary title.

He has been more open than some in National might deem to be advisable.

Walking away from this deal would be political madness. Harawira's campaign against the bill would make sense if there was a better offer. Unless the Greens lead the next Government, that is highly unlikely.

The cold hard reality is that there is now an opportunity to settle this vexed issue. Act and the Coastal Coalition - the umbrella lobby group fighting the legislation - have not succeeded in mobilising public opinion.

But it might take only one or two more developments like this week's occupation of a Northland yacht club by Harawira's nephews for Pakeha opinion to begin to turn.

Harawira would like the bill to be dumped. So a Pakeha backlash might suit his cause. But while he is free to vote against the bill, that does not give him licence to undermine his party's position. It would not happen in other parties. Disagreement is one thing; outright dissent is a completely different kettle of kai moana.

Things may work differently in the Maori Party, but his claim to be the only one who "takes Maori issues to the edge ... who speaks for the hearts and minds of the ordinary Maori" must be hard for his parliamentary colleagues to stomach.

Presumably they tolerate it because he speaks for a particularly volatile voter catchment and, therefore, it is better to have him inside the tent than out.

That goes to the nub of it. One of MMP's virtues is that it brings into Parliament firebrands and radicals who would otherwise be shut out of the "system".

They are forced to choose between working with the system or standing on the sidelines and drifting into irrelevancy.

Sue Bradford is a prime example. She worked the system, most notably with her bill banning smacking.

She did so with the disadvantage of being an Opposition MP, although the Greens did have co-operation agreements with Labour for certain periods during the last Government .

Harawira is someone with obvious energy and commitment and clearly has a strong rapport with his people, so it's a pity he does not make more of the Maori Party's current access to the levers of power.

Instead, he announced this week that he had realised that his role in Parliament was to continue the "activist tradition".

When he asked himself whether he should play the game by the rules, the reply he got was "why should I?"

That amounts to an abdication of the responsibility he has to work in the best interests of his party.

We should expect his letter of resignation from Parliament soonest. But don't hold your breath.