Time to feel sorry for Alistair Darling?

Mr Cameron draws on the legacy of late Labour leader John Smith in his defence of the Union, but is unlikely to cite Margaret Thatcher

And so, we are informed, the prime minister, while campaigning in Scotland, will cite the former Labour leader John Smith in defence of the Union.

Imagine if he had summoned another former party leader who was a staunch supporter of the Union. One who was rather closer to the PM's own political standpoint. In short, Margaret Thatcher.

How do you suppose that would have gone down in Scotland? Yes, thought you might say that.

The point is, of course, wicked - and somewhat specious. The PM is drawing upon the legacy of John Smith not just because he was popular in Scotland - but because he was a Scot.

David Cameron's argument is that it is possible to be a patriotic Scot while accepting, indeed endorsing, Scotland's continued participation in the wider Union, in the British State.

Nonetheless, it is a legitimate source of innocent merriment to try other names in the frame. By doing so, one reflects that the Tories remain deeply unpopular in Scotland and that, as a consequence, many in Scottish Labour are somewhat uncomfortable at the connection between the two parties in Better Together.

Time, perhaps, to feel sorry for Alistair Darling. Just a bit? What, not at all? Gosh, you are in a grumpy mood this morning.

Figurehead

Reflect. At the outset, Alistair Darling did not want to head up Better Together. Just think of the approach phone call. "Hi Alistair, I know you've spent umpteen years in Cabinet. I know, I know, the last few years were a bit tough - Royal Bank, global financial collapse, yada yada. But how do you fancy spending the next few years herding cats in defence of the Union?"

Alistair Darling was given an early assurance that he would be a figurehead for the Better Together campaign

Eventually, Mr Darling agreed - but was given an early assurance that he would be primarily a figurehead, that there would be a triumvirate of parties on board, with big names striving constantly. Didn't quite happen, at least in the first phase.

So Mr Darling decided if he was going to do it, he might as well do it thoroughly. Which he did. Then there's a bit of movement in the polls towards Yes, the UK general election looms and tension rises on both counts. Result? A rather loud if imprecise whispering campaign against A. Darling.

Has he been "sacked"? No. Is there tension within the Better Together camp? Yes. Where does the tension lie? Between Tory and Labour. Between Westminster and Edinburgh. Between less than mutually friendly elements in Labour.

Does it matter? Yes, if it weakens the pro-Union pitch and gives encouragement to the pro-independence side. Beyond that, does it matter to the voters? Not by comparison with issues such as pensions, welfare and the broad economy.

Momentum

Has there been tension in the Yes Scotland camp? Yes. Where did it/does it lie? Between the SNP and other participants who have a different vision of independence. In the past, within the Yes Scotland team. Does it matter? See above.

Right now, the momentum appears to be with the "Yes" camp. They believe that a further intervention by a Tory prime minister simply serves to remind Scots why they endorsed devolution in the first place - and might impel them towards independence. They underline that point by challenging Mr Cameron to debate Alex Salmond head to head.

The pro-Union side believe they can reinforce popular anxiety about the independence project by continuing to emphasise the alleged economic downside. Hence the plan by the Treasury to publish an assessment of independence which, we are told, will contain a simple sum suggesting how much it would cost the people of Scotland.

Expect that after the European Elections. Expect it to be contested vigorously by supporters of independence who will say that it neglects the growth potential of a small, vigorous nation. Expect more, much more. Your referendum, your choice.