Key Points:

Is it the case that the legislation is now hopelessly tainted - or is it simply that the minister in charge of the flawed and unpalatable Electoral Finance Bill seems helplessly doomed?

Probably both. When Mark Burton gets up in Parliament to defend the bill - as he has to do every sitting day - the Justice Minister gets minimal assistance from colleagues around him.

Their heads go down. They seem suddenly otherwise occupied. They do not ask patsy questions to give him some respite from National's Bill English, whose detailed grasp of the legislation's provisions has been making question-time a nightmare for the minister.

Mr Burton finds himself out on a limb. Judging by colleagues' reactions, the Prime Minister has her saw poised to lop off the branch.

With the words "Cabinet reshuffle" looming ominously over the Labour benches, National's Burton-baiting reached its zenith during yesterday's free-for-all general debate.

Simon Power suggested Mr Burton had been too slow to recognise that, as the front-man for the bill, he had been set up. His sloppy handling of the measure had given the Prime Minister the excuse she needed to remove him from the Cabinet.

"He has effectively paved his own way to the exit door. He didn't see that one coming."

Someone who apparently did see it coming was Damien O'Connor - at least according to John Key.

Saying the probable scale of the pending reshuffle would be equivalent to open-heart surgery for Labour, National's leader suggested somewhat tongue in cheek that Mr O'Connor had managed to keep his job by texting the Prime Minister that he did not want it.

He knew she could not accept his offer to resign because she was in the middle of a major reshuffle and he would have to stay in the job until she was ready to unveil it.

But if he stays and Mr Burton goes, the latter will have grounds for appeal.

Mr Burton's plodding defence of the Electoral Finance Bill pales into relative insignificance compared to Mr O'Connor's own-goal as Corrections Minister in allowing a suspended prison officer to accompany him on the parliamentary rugby team's pre-World Cup trip to France.

Yet when Mr Key listed some of the things that had gone wrong in the Corrections portfolio under Mr O'Connor's watch, the Prime Minister first expressed confidence in the minister in his absence and then defended him by pointing to a sharp reduction in prison escapes and assaults.

Phil Goff helpfully supplied the figures on prison escapes under Labour and National administrations.

Seemingly even more helpful was Winston Peters, who slammed National for hounding someone for playing a simple game of rugby.

However, it soon became apparent Mr Peters was talking about Jim Morgan, the prison officer.

National is hounding Mr O'Connor, not him. And Mr Key got the crux of the matter by asking the Prime Minister if she could give an assurance Mr O'Connor would remain in the Corrections portfolio after the reshuffle.

"No more than Mr English would give a guarantee of continued support for Mr Key," the Prime Minister chortled in response. She had avoided the question. Deliberately.

Unless there are further retirement announcements soon, someone will have to go to make room for fresh faces at the Cabinet table. In the meantime, Mr O'Connor, Mr Burton and Rick Barker - another minister being tagged for possible demotion - are playing Cabinet's equivalent of musical chairs.

Judging from Parliament yesterday, Mr O'Connor can be more optimistic of still having a seat when the music stops.