Dunne will also have no National candidate standing against him in Ohariu-Belmont. But there's a price. Not policy - United has little enough of of that. National wants Dunne to urge his local voters to confer their MMP list vote on National. National needs list votes - otherwise it runs the risk of returning so many electorate MPs that hardly anyone on its list gets in.
Labour is in a similar position.
If it entered anything that looked like a coalition with the Alliance, the temptation for left-leaning voters to return their trusted Labour candidate and then give their list vote to that nice Mr Anderton could be pure poison. The pressure would come on to have Anderton lead the coalition - in which case, exit most of the Parliamentary Labour Party and reduction of said party to tenant of the feudal realms of the Alliance. Anderton should have expressed his disappointment and shut up. But he didn't. Very tasteless indeed.