Today's deal between the Maori Party and the Mana Movement was signed with a great deal more hoopla and harmony than is normally associated with such electoral accommodations.

That may be because it is not like other agreements.

For one thing, it is asymmetrical in the extreme - one for six. Maori Party will not stand against Hone Harawira in his former electorate of Te Tai Tokerau and his Mana Movement will not stand in the six other electorates.

They will compete for the party vote across the country but not in any single seat.

Advertisement

Second, it is a deal between former bitter foes. This rapprochement is brings together feuding factions of the Maori Party and its break-away arm, Mana. They needed a highly publicised memorable occasion to begin eroding the layers of antipathy built up since Harawira left in 2011.

But what makes this deal so different to the others is the degree to which they will support each other and sing the praises of the other as electorate candidates.

The deal in theory means parties stand aside for the other in given electorates. In practice it appears to go further.

The Maori Party president Tukoroirangi Morgan strongly endorsed Harawira's election in the north.

"We must galvanise ourselves to make sure Hone gets back into Parliament," he said.

According to Maori Party co-leader and list MP Marama Fox, the Mana Movement organisation in Ikaroa Rawhiti had already swung in behind her bid to take the seat off Labour's Meka Whaitiri.

Joint campaigning, let alone vocal endorsement by parties has not been a feature of any other electoral accommodation.

National leaders have had the odd tactical tea or coffee date with Act Epsom candidates to send a signal to their supporters. National Party sensibilities are deemed to be too tender to send a direct message to vote for the Act candidate.

The Greens have similar sensibilities. They announced last week they will not stand in the Ohariu seat in order to help Labour's Greg O'Connor loosen Peter Dunne's paua-like grip on it but they won't go so far as to advise Green supporters to vote for O'Connor.

For the Maori and Mana parties, there is no such subtlety. They want the Maori seats "back in Maori hands," as Harawira puts it.

Despite its lopsidedness, it's a deal both parties could both benefit from, in equal measure. If Harawira reclaims Te Tai Tokerau from Labour's Kelvin Davis, he can bring in other MPs on the list, possibly Annette Sykes.

That leaves the Maori Party to concentrate on gaining more than the single Maori seat that co-leader Te Ururoa Flavell holds.

Besides Te Tai Tokerau, the combined vote of Maori and Mana in the 2014 election was higher than Labour in two other electorates, the Auckland seat of Tamaki Makaurau, and the western Maori seat of Te Tai Hauauru, both of which were vacated by former Maori Party co-leaders Pita Sharples and Tariana Turia.

It will be an easier contest for the Maori Party without Mana in those seats but it is by no means even likely that it will win, even with strong endorsement by the other.

Labour MPs Peeni Henare and Adrian Rurawhe have had three years of incumbency.

The biggest risk for Maori Mana deal is that it is too successful. While their co-operation agreement expires at the election, if they are seen as joined at the hip, they may become liabilities for the other in election year.

When Harawira hits some bum notes in the campaign - let's assume there will be some - they may rub off on the Maori Party by sheer association.

Harawira has no such qualms. He likened the deal to Joe Walsh coming to play with Herbs, saying "you can mix bands and still make good music".