James understands the dynamics of coalition government rather better than Simon Heffer. This may not surprise you. Mr Heffer complains that by letting Vince Cable survive - albeit in gelded form - while dumping the likes of Lord Young for other more trivial indiscretions, the Prime Minister is guilty of setting double standards.
One would be appalled if this were not the case. And the double standard - for such there certainly is since Lib Dems may, indeed must, be opposed to at least some parts of coalition policy - reminds us that this is a Tory government leavened by the Liberal Democrats, not a Liberal Democrat government with added bits of light blue. For 80% of the country this is not news. Most people, spying Mr Cameron, have no difficulty identifying the Prime Minister as a Conservative.
Which is why he can appear to be generous to poor old Cable. Appear, I say, since Cable's influence is shot to pieces. But Cameron appreciates, I think, that the intricacies of coalition are such that the junior partner must be permitted the occasional piece of freelancing or grandstanding if the greater enterprise is to survive.
Contrary to conventional wisdom, the coalition depends upon Tory goodwill much more than it does on the Liberal Democrats' continued enthusiasm for government. Coalitions fall when the senior partner makes life too miserable for the junior player. In that sense, then, the Prime Minister does need to heed the rumblings of discontent within the Conservative party, if only because they threaten him rather more than Liberal Democrat disgruntlement does.
Or, to put it another way, the Liberal Democrat leadership is painfully aware that their survival depends upon the coalition lasting and, rather importantly, eventually being seen as a success. An election next year is not likely to produce much good news for the Liberal Democrats. Their self-interest is fixed to the coalition's own interest. It is, however, less obvious that the Conservative party appreciates that its interest is also tied to the success or failure of the government.
That is, there is little evidence or reason to suppose that the Conservatives would necessarily benefit from the collapse of the coalition. Would the country really see the fall of a government that is 80% Tory as grounds for electing a 100% Conservative government? It's not obvious to me that the public would take this view.
As a general rule, elections are best avoided until the moment is propitious or unavoidable. There's no good reason for this government to fall, far less to thrust another election upon a public that has no particular desire for such a contest. (A minority Tory ministry is, I suppose, theoretically possible but, surely, would only be a poor and short-lived thing.) That does mean that the survival of the coalition is both an end in itself and means to another end: a second term for Prime Minister Cameron.
In turn that requires a certain generosity and tolerance for dissent. It may appear as though the minor partner has the whip hand but in fact real power is retained by the majority. The Lib Dems face regular trials of fortitude; the Tory leadership very few. It can scarcely be otherwise when, as I say, 80% of the power is concentrated in Tory hands. But precisely because the arrangement is so lop-sided concessions to the Lib Dems must receive much more publicity (because they are relatively rare) than should the implementation of Tory policies.
Keeping the Lib Dems reasonably content is an important part of managing the coalition; so too however is reminding the Tory party that a) it gets most of what it wants anyway, b) its own interests (that is, a second term) depend upon the success of the Dave and Nick Show. Like it or not, the parties stand together which also rather means that they can fall together too.