The likely victims will need to make a reasoned assesment of their choices:

(1) What is the chance of retaining their seat for Labour ?
(2) To whom are they most likely to lose it ?
(3) Do they have an alternative career / job lined up ?
(4) If they defect, would their new party allow them to stand as its candidate ?
(5) Even if answer to (4) is yes, what is the chance of holding their seat for teh new party ?

Only those who can get a positive response on (3) and / or (5) have any incentive to jump ship or force an early election.

Some may calculate that the answer to (1) is better now than later, but if they force an early election, would that backfire on them ?

One option under (3) is a seat in the Lords – but that will go up in smoke if they rock the boat.

The answer to (2) could be a major factor which limits their options – especially combined with (4). Some may be tempted to defect to LDs in the hope of standing and defeating a Tory threat. However, the track record of defectors standing in their old constituency is not good, while neither Con nor LD are going to allow some failed Lab MP to carpet-bag their most promising targets, still less a safe seat (not that the LDs have any to offer).

So, all in all, don’t expect many defectors or Labour MPs willing to vote against Brown on a confidence motion – however bad things look.

But Brett-Chorley is most likely to be correct, unless there is some unexpected event.

1974 Oct 43.8% 37.4% 17%
1979 39.6% 46.0% 11.2%
1983 29.8% 43.9% 24.7%
1987 31.5% 46.5% 21.1%
1992 37.2% 45.4% 14.7%
1997 49.6% 31.2% 14.3%