The speeding up of turnover rates has almost nothing to do with shifts to the right or left, and much more to do with wider cultural change in Parliament.
Many are choosing to depart at an age which would have been very unusual in earlier times, and each gives Johnson a new chance to reshape the parliamentary party.
Margot James resigned as a minister following her rebellion. Meanwhile, the Chancellor joined Gauke and Clark in failing to support the Government.
The list includes the three who resigned from the Government this evening – and Green, one of the Prime Minister’s oldest allies.
In the night’s only defeat for the Government, it passed by 318 votes to 310 – and with the largest rebellion from Conservative MPs.
We also reproduce the full text of the letter itself.
Some favour a Second Referendum; others, EEA membership. But they have combined to deal the Prime Minister a second bloody blow in a single day.
The presence of four Labour Leavers helped the UK to avoid a customs union – but their absence on a more minor amendment produced a Government defeat.
A list of new Tory Reform Group patron MPs suggests that it is stronger in the Commons than it may look.
Clarke, Grieve, Morgan, Soubry, Neill, Stephen Hammond, Wollaston, Sandbach and Lefroy back major changes to the Bill (as do some Brexiteers)
A vocal Brexiteer, a vocal critic of the Government’s plans, and two newly-elected MPs (Simon Clarke and Vicky Ford) were unsuccessful in the race.
All but two of those elected are from the 2010, 2015 and 2017 intakes.
Twenty five Tory MPs joined Labour and the SNP in opposing liberalisation, and provided the Government’s margin of defeat.
The number of rebels has risen; it is concentrated among post-2005 intake Tories, and in seats that are either marginal or were until recently.