Matt McCarten stands for Mana, promising to "change the campaign"

The union boss is taking his show on the road... all the way to Mana. McCarten wants to "make them work for it", and it's a safe bet both Labour and National will be on the receiving end of his sharp tongue

Matt McCarten is either an adorable mischief-maker or a dangerous revolutionary, depending on who you talk to. But what everyone can agree on is that he is one of the sharpest political minds around, so when you learn, as we have this morning, that he's standing in the Mana by-election you know something's up.

That's right, McCarten is going to stand in Mana. Unashamedly carpetbagging it. The by-election takes place on November 20, with Labour standing Kris Faafoi and National putting up Hekia Parata.

As he told me, he wants to "raise some questions and make them work". He laughed off questions about whether he'd move to Mana if he won, but said he was asking Mana people to invite him into their community and reckons he can "change the nature of the campaign".

He'll be endorsed by his UNITE union but will be an independent arguing for workers' rights. Don't you just love how by-elections are so unpredictable? When you're not voting for a whole government, both political animals and the general public can feel free to chance their arm a bit.

Labour had hoped the the wild card in this by-election was going to be a working class suburb giving the finger to the government on the cost of living and a stalled economy. Now, they'll be fuming.

Honestly, from Chris Carter via The Hobbit and all the way to McCarten, Phil Goff just can't catch a break. Just when he looks like he might get a bit of speed up, the road turns and he has to throttle down.

National, on the other hand will have a glint in its eye, thinking 'just maybe...'

The obvious danger is that McCarten splits the left vote, perhaps even allowing Parata to win, embarrassing Labour and ruining Phil Goff in the process. Some on the left will see it as a betrayal. McCarten, I suspect, feels no great loyalty to Labour in general and Goff in particular, so doesn't give a toss. He wants to show Labour how to fight for its core constituency.

He's always been a servant of the cause, unwilling to bow to any other.

So it's hardly surprising when he says his platform will be workers' rights. He wants to keep hammering National on its tax cuts, push Labour on its tax policy (a commitment to return GSt to 12.5%, anyone), and agitate for a $15 minimum wage, government employment schemes and a Living Wage Commission, "to look at what it would mean for people to live with dignity on a living wage".

McCarten is old school. His solution to unemployment in Mana? Offer unemployed folk training at the local wananga in a few quick courses and get them fixing up state houses and helping out in local schools for $15 an hour.

Screw the market, it's failed these people, so it's up to the government to get them into jobs and onto a wage.

Oh, yes, Mana is suddenly in the news, and so will McCarten's issues. It just became anyone's race.