David Cameron will tell Scots this morning that the UK wants Scotland to stay a part of the Union. That he’s giving this speech at all is being read in some quarters as a sign that he’s at least underwhelmed by the show put on so far by Better Together leader Alistair Darling. The PM’s intervention certainly marks a change of tone from the most recent speeches, particularly Mark Carney’s, which George Osborne praised as a very good ‘technical’ speech. Thus far the ‘no’ campaign has relied more on the technical argument which Alex Salmond has brushed away as minor objections to the great principle of independence. So Cameron is making the emotional case.

In this week’s Spectator, Alex Massie argues that this emotional case is far more powerful:

They do have one powerful card to play: Britishness. The SNP do not, in fact, want to talk about losing this identity — at least, not openly. Perhaps because, despite everything, Britishness still has a surprising appeal: Scots cheered Jessica Ennis at the Olympics as a countryman. Andy Murray draped himself in a Union flag at Wimbledon last year. This is still the country of Shakespeare and Burns, Dickens and Scott. What unites us — in culture, politics and temperament — is far greater than anything that divides us. Salmond argues that England should prefer a good neighbour to a ‘surly lodger’, forgetting that many Scots do not think themselves mere lodgers in Britain. It is their home.

And that’s exactly the card that Cameron will play today. Speaking in the Olympic park, he will say:

‘For me, the best thing about the Olympics wasn’t the winning. It was the red, the white, the blue. It was the summer that patriotism came out of the shadows and into the sun. Everyone cheering as one for Team GB. And it’s Team GB I want to talk about today. Our United Kingdom.’

But as Alex observes in his piece, the emotional pull of he nationalist cause makes the ‘no’ campaign’s job much, much harder. And Cameron’s own role in that campaign is a tricky one, too: he is speaking today but didn’t want to drive his message home by popping up on the Today programme too. Instead he sent Labour’s Tessa Jowell to soften the Tory blow.

Tags: David Cameron, Scottish independence, SNP, UK politics