A party working towards a third term in government often looks stale and in need of refreshment.
National doesn’t have that problem.
It gained new MPs in both 2008 and 2011 and with resignations and retirements can expect a good number of new members after this year’s election.
Labour by contrast is in opposition and looking stale.
Only one of their MPs, Ross Robertson, has announced his retirement. Since no-one else is jumping they’re going to get a push:
. . . Mr Cunliffe also said he and deputy leader David Parker will meet with each of the MPs individually over the next fortnight and were already in discussions with some about their political futures within Labour. “There are one or two conversations with one or two colleagues that go to their long-term planning, but that is a private matter between them and the leadership team.” He would not say if they had approached him or he had shoulder tapped them. “We’ve got processes in place where we are setting goals for all our colleagues.” . . .
One reason for National’s renewal is that its MPs have other options and plenty of other things to do with their lives.
Many sacrificed income to go into parliament and can expect to earn more out of it.
The reluctance of Labour MPs to go graciously suggests they don’t have those options.
The caucus is already unstable, having to work under a leader a majority of them didn’t regard as their first choice.
Disgruntled MPs who feel they’re being pushed out will have nothing to lose if they let their disloyalty get in the way of caucus unity and their party’s best interests.