It is somehow typical of Nick Clegg's fate that a speech ostensibly designed to distance himself from David Cameron has already been defined by the phrase "muscular liberalism". After all, it was that same clunky label which Cameron used to describe his approach to multiculturalism in the speech that angered so many in Clegg's party.
Based on the extracts I've seen, the Lib Dem leader's address on "The Coalition and Liberal Politics" will be dominated by the argument that the coaliton is one of "necessity, not of conviction", a temporary alliance rather than an ideological union.
He will say:
There has also been some talk of a so-called centre-right "realignment" since the formation of the current coalition. This is just nonsensical and naive. As I said earlier, this is a coalition of necessity, not of conviction. Realignment consists in practice of two-party political system continued by other means. It is a polite euphemism used by people who want to continue the fight between one gang and the other gang – with us as a temporary recruit to one side. I didn't come into politics to simply replicate the two-party system under the guise of realignment. That's not my definition of pluralism.
Yet the difficulty for Clegg is that, like Cameron, he has frequently given the impression that he is happier sharing power with the Conservatives than he would be governing alone. The foreword to the coalition agreement, for instance, declared:
We have found that a combination of our parties' best ideas and attitudes has produced a programme for government that is more radical and comprehensive than our individual manifestos.
All the same, it's safe to conclude that we won't see a Tory-Lib Dem pact or anything like it at the next general election. But perhaps the most notable thing about Clegg's speech is the scepticism, and even contempt, with which he treats the idea of a "progressive alliance".
"There are still those who dream of a so-called 'progressive alliance'," he will say, "forgetting that Labour had 13 years to make some moves in that direction and never quite seemed to get around to it until, in desperation, they tried to cling to power last year."
That's a none-too-subtle rebuke to those such as Vince Cable and Chris Huhne who boasted that the adoption of the Alternative Vote would finally make the dream of a "progressive majority" a reality. It's also yet more evidence that Clegg is in no mood to forge the roots of a future alliance with Labour.
The Liberal Democrats, he insists, will stand their ground "in the liberal centre of British politics", neither the "anti-Tory party [nor] the anti-Labour pary". Once more, there is an obvious contrast with Cable, who argued that AV would prevent another Conservative century.
It's a bold declaration by Clegg and one, you feel, that won't do his potential challengers on the left any harm.