Coalition: Official - it's not a marriage

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Media captionNick Robinson witnesses the pair "still laughing at each other's jokes"

It's not a marriage. It never was. They were never in love so they are not renewing their vows.

That, in summary, is the reaction inside Downing Street to how the media, including me, have spoken about today's joint news conference to be held at Downing Street by David Cameron and Nick Clegg.

The coalition was, the official line goes, always a business partnership forced on both sides by events. Today is, therefore, a business-like review of goals achieved, those still to be met and a few new ones.

The reason this debate about terminology is revealing is that both sides of this coalition have concluded that all this talk of marriage is toxic as it invites hacks like me to conclude that the Tory and Lib Dem partners are still "in love" - something which infuriates many of their natural supporters - or preparing to "divorce" in the run-up to the next election.

The Cameron/Clegg talk of their strengthened "shared purpose" was, of course, always going to make it hard to resist the temptation to ask whether both men are protesting too much. I doubt that many hacks today will resist.

Put to one side the debates about metaphors: what is the state of the coalition?

Last year's public rows about voting systems, House of Lords reform, boundary changes and Leveson fuelled the idea that this government was beginning to fall apart. Whisper who dares, it is not. In fact, relations at the top of this government are better than in many single party governments (led by Wilson, Heath, Thatcher, Major to name a few) faced with a comparable record of economic woe.

Read back that list of coalition disagreements and it reminds you that they were issues on the margins of most voters' concerns whereas there is a surprising degree of cross party agreement on macro-economic policy, welfare cuts and schools reform let alone the proposals the two men will highlight today - be it childcare subsidies, pension reform or road tolls.

That is not to say that all is well in the coalition rose garden. It is not. However well the partners get on, their extended families (sorry, here I go again) can't stand the sight of each other. Many Tories believe their leader betrayed them when he got into bed with Nick Clegg. And now there's a new man trying to woo those whose hearts have been broken - that smooth talking, blazer wearing, risqué man puffing on an untipped cigarette and holding a pint of real English ale. I speak, of course, of Mr Nigel Farage of UKIP.

Unlike any marriage or business partnership or, indeed, any post war government, the Conservatives and the Liberal Democrats know not just that they are doomed to split, not just the date (May 2015) but also that to regain lost support they need to convince people (or relatives or shareholders - take your pick) that whilst they are not in love, whilst there is much they don't agree on they are still capable of doing an awful lot together.

PS Interesting news that Lord Hill is replacing Lord Strathclyde as Leader of the House of Lords. Jonathan Hill was political secretary to a prime minister who was caught referring to four members of the cabinet as "bastards." After life at John Major's side, handling Lib Dem peers should feel like a doddle.