Philip Cowley and Mark Stuart, from the University of Nottingham, have been looking at how often backbench government MPs have been rebelling in this Parliament:

Out of the first 110 divisions in the Commons since Parliament resumed, there have been rebellions by government MPs in 59. That is a rate of rebellion of 54%, simply without parallel in the post-war era…

The Conservative rebellion rate of 35% … is higher than the rate of rebellion by government MPs in all but four of the post-war sessions. The Lib Dem rate of 28% is higher than that seen by government MPs in all but seven post-war sessions. (It is also noticeably higher than the rate of rebellion seen by Lib Dems in any session for which we have data, going back to1992-93 when the rate of rebellion was at 9%)…

For all that, at no point since May has the Government’s majority been in any way threatened. The lowest Government majority thus far has been 58.

For one thing, although the frequency of rebellions is alarmingly high, the average rebellion is small, comprising just six MPs. (The average Conservative rebellion is seven MPs, the average Liberal Democrat revolt is even lower at just three MPs). The largest Coalition rebellion thus far – on Europe – involved 37 Conservative MPs, not enough to threaten the Government’s majority, not least because the Labour Opposition frontbench abstained. The largest Lib Dem rebellion saw ten MPs support Charles Kennedy’s amendment during the Report stage of the Parliamentary Voting System and Constituencies Bill that would have made numerous exceptions for preserving large islands and large geographical areas as whole constituencies.

And second, so far the two sets of Coalition rebels – Conservative and Liberal Democrats – only rarely vote against the Government on the same types of issues.

That last point highlights an important asymmetry which points to the Coalition lasting for a longer rather than shorter time. When it comes to rebellions from the backbenches, it is predominantly one party or the other which has unhappy backbenchers. However, when it comes to disagreements at ministerial levels within the Coalition, the tensions have not been between the two parties in coalition; rather, they have been along shifting lines that cut-across parties. Ministers agreeing with each other across party lines yet rebellious backbenchers not doing so is almost the perfect combination for the Coalition’s long term survival.

It also shows how Liberal Democrat ministers are – so far – much more successful at finding allies in Conservative ranks (most notably over immigration, Trident and control orders, where heavyweight Conservatives have been arguing for the same policies as Liberal Democrats) than rebellious Liberal Democrat MPs, who have tended to rebel on issues that might win Labour, but not Conservative, backing.

A coalition with wobbly wings: Backbench dissent since May 2010