I also want to bury the notion that the law is needed to protect the proportionality of Parliament and the party vote. There are many aspects of MMP in which pure proportionality is not followed: there's the 5 percent rule; there's the rule where an MP may resign and cause a by-election, as occurred in Northland; and there's rules about when their seats can be vacant for six months. There is also the legitimate question as to whether an MP leaves the party or whether the party leaves the MP, that was so eloquently put by Jim Anderton when he left Labour in 1989. The same can be said of defectors like Derek Quigley and Marilyn Waring: the principled one can actually sometimes be the MP rather than the party. 