Despite the turbulence caused by the Right of the Tory Party and the Left of the Liberal Democrats and while the partnership has been badly shaken, the fact is neither the Prime Minister nor the Deputy Prime Minister or their respective colleagues have anywhere else to go.
If the Coalition were to split asunder tomorrow, then the Tories might be able to struggle on for a few weeks as a minority government before there was a vote of confidence, which they would lose, and the country would go to the polls.
Who could confidently predict Mr Cameron would remain as Prime Minister?
Meantime, the LibDems, struggling to break above 10% in the polls – 7% in Scotland – need a relatively quick election like a hole in the head.
The only salvation they might be able to find from electoral wipeout is if by 2015 they can convince the public:
(a) The economy was being turned round and they were partially responsible;
(b) Coalition politics actually worked; and
(c) they ameliorated the nastier habits of their Conservative bed-fellows.
There has been much talk of how in the last 12 months before the 2015 General Election, the LibDems will break free from the Coalition.
Yet senior LibDem ministers have told this newspaper the public would not be convinced by such a move; that it would look like shameless electoral manoeuvring and the voters would see it for what it was.
And, of course, they'd be right. However, uneasy and painful the Coalition makes some parts of both parties, the leadership knows that each, to use a well-worn phrase, is better together; so it's 2015 or bust.