By: Mike Hosking | Monday, September 17, 2012 7:41 AM

If MMP has one great failing - it actually has a number of failings - but the one that keeps coming up is the reliance major parties have on small parties and quite often individuals. The latest is John Banks.

Simple question - if John Key had a majority of 12, would Banks still be in Cabinet? Another simple question - when John Key was asked on Friday whether he was still standing by Banks did he look A. uncomfortable, B. embarrassed or C. both? But that's the system isn’t it. Alamein Kopu was similar. Remember her? Complete waste of space but Shipley needed her vote and she was accommodated in the most absurd of circumstances.

This is of course was what the pro-MMP campaigners promised wouldn’t happen when the charge was raised before we elected it as our electoral system. The tail would wag the dog - no it wouldn't they said. They were wrong.

So in the Banks case National are tainted by association the same way they’re tainted by the Maori Party and their various issues over water and the Treaty. The only one who seems to have kept his head down and got on with it is Peter Dunne.

But in the Banks case it’s beyond policy, it’s about integrity and personal behaviour and as much as Banks argues it’s done and there are no charges, it has spread beyond him to the National Party. Banks can test his support in two years and that's as it should be. He’s answerable to the people of his electorate and if they don’t like what’s happened, he’ll be gone.

But look at the trouble National’s landed themselves in. The cup of tea, the direction to vote for a party other than their own - none of which I had any problem with by the way given that's the way MMP works. You have to cut deals. But now I think even the strongest Banks supporter would have to concede that the only reason at least one charge appears wasn’t laid was because time had run out. The person who’s become the most famous for getting away with stuff under similar circumstances is Silvio Berlusconi.

So is Banks the Silvio of NZ politics? And if he is, where does that leave poor old Key who has little choice but to hold his nose and hope it all goes away. It is at best a messy business, at worst a complete shambles that might well end up affecting all those touched by it. It’s one of the major issues governments run a mile from, the taint of the sordid. Governments that look to be making decisions merely to survive or keep their numbers are not well thought of. MMP has provided too many of them.

The only upside is that the next election is two years off and people have short memories. I think both parties in this case will be hoping that remains true.