John Armstrong: Labour left with no choice but censure

So what does Labour do about Phillip Field now? Having spent the best part of two days quietly trying to cajole the Mangere MP into leaving Parliament - or at least flagging his intention not to stand again - the Labour leadership has got precisely nowhere. The "managed exit" strategy lies in ruins.

Meanwhile, the whole sorry affair explodes ever messier in Labour's face.

The Opposition runs daily more rampant in Parliament. Labour is no longer setting the political agenda. Now there is evidence in the form of poll data that the affair - or rather Labour's cynical handling of it - is hurting Labour by contributing to a cocktail of negative factors which National places under the umbrella term of "corrupt government".

Apart from Labour's overall support lagging nearly eight points behind National, the latest Herald-DigiPoll sees support for Labour tumbling at the upper end of the crucial middle-income voting segment.

More crushing perhaps - as National was quick to point out - the Prime Minister for once has not got her way.

Mr Field has snubbed her open invitation to at least declare he will be stepping down at the next election. He insists he has done nothing illegal. He is digging in his heels.

It is a rare defeat for Helen Clark. It would go too far to say she has been humiliated. The affair represents the limits on prime ministerial power in having no sanctions to wield against a backbench MP.

She and Labour are not powerless to express disapproval by censuring the MP. The party's ruling council, which meets this weekend, risks looking ineffectual if it lets an individual's self-interest override the party's collective need to deal with something corrosive to morale and voter support.

Yet the obvious solution rests in Labour hands - a full independent inquiry that would settle matters and stop National exploiting the limbo. But that would mean conceding that Labour has totally mismanaged things since the Ingram report was released six weeks ago.

Back then Labour thought it could tough it out because it thought it could get away with doing nothing in terms of disciplining its MP. Now it looks like it is going to have to tough it out with all the unpleasant consequences because Mr Field has left it no choice.