Is Ed Miliband dishonest, dim, or a bit of both?

That's a hard question to ask of anyone who thinks he can walk in the shoes of a Clement Attlee or a Harold Wilson. To ask it of someone who believes he is able to run a country is harder still.

The question of honesty is probably easiest. During the last of the TV political debates, Mr Miliband stated, bluntly enough, that he will make no accommodation with the Scottish National Party if Labour cannot form a majority unaided next week. Was that truthful? If so, the consequences hardly need to be stated.

It amounts to Labour's leader saying, first, that he will give up an opportunity for which he has worked all his life. Secondly, Mr Miliband would be asserting that seeing David Cameron's Conservatives back in power would be preferable to anything involving the SNP. Those £12 billion of Tory benefits cuts; the resumption of slash-and-burn austerity; the collapse in UK productivity: this is not trivia.

Polite opinion assumes, then, that Mr Miliband is not being honest; that of course he will accept a call from Nicola Sturgeon on May 8; that sheer ambition will prevail. After all, short of an unprecedented change in public opinion, a Labour majority is not going to happen next week. My two bob is still on another election in the autumn, but that will keep. For now, there is something else for Ralph Miliband's son to consider: being dishonest with the voters is not a good start.

You discern, in the choice he has declared, a politician who does not grasp the difference between tactics and strategy. To shore up a Labour vote in England and "defuse" some desperate Tory attacks he will write off Scotland? To protect and serve the United Kingdom he will drive a stake into the idea of a shared country? What kind of Labour Party, if any, does Mr Miliband imagine will emerge?

Like many, I could say something about all those "passionate" promises during the referendum and what, it transpires, British politicians really think of the Scottish bit of these islands. That's where "dim" becomes part of the argument. It seems Mr Miliband means to win power by preparing the kind of constitutional crisis he used to warn against. I would not call that clever.

As of this year and this election, the SNP are a fact of UK political life. They tilt every balance, touch every London calculation. To say you will have no truck with them is an insult, obviously, to many voters. It also shows a strange attitude towards legal democratic politics. But for a working politician dealing with dismal polls it displays - what shall we say? - a lack of mental agility. There's the SNP and there's the Scottish vote: get used to it.

I know, from personal experience, that Ms Sturgeon has intrigued and excited people in England. They like what she has to say and the way she says it. Those voters ask some baffled questions. "What," they want to know, "is the real difference between the SNP and Labour?" I put on my best political anorak and reply, "Not as much as either party would have you believe, except in two things: austerity nonsense and Trident".

Mr Miliband, as it happens, was specifying those items in interviews yesterday. Apparently, his claimed refusal to budge on either issue was supposed to reassure the voters of England. Do they truly need reassurance? If so, the game is up for the Union. If not, he is being cavalier with their faith. He is not behaving like a Labour leader. Loathing the SNP is a ritual from another age, one in which Mr Miliband's party still existed in Scotland.

All of us are still adjusting to new realities. Those of us who are not precisely youthful still find it hard to believe how completely Labour has collapsed in Scotland. Those who have youth find nothing remarkable in the phenomenon: they saw it coming and they help to make it happen. If Mr Miliband is using his wits, he could take another lesson from those voters. They say that, if Labour has ceased to function in Scotland, their survival anywhere is open to question.

The party's leader, young enough himself, already resembles an antique. The era in which parties were big enough to dismiss upstart rivals is over. Taking refuge in the ruses of the Commons and the British Establishment won't do. When first-past-the-post fails, the game's up. And who now doubts that the electoral system, shield and armour to Westminster for a century, is no longer "delivering" for its sponsors?

Mr Miliband has made a choice between his focus groups and what used to be his party in Scotland. The spectacle leaves a sour taste. Even those who have defended the Union stoutly might pause to wonder what Labour's leader means to convey. That any Scottish voter who does not pick his party must be ignored? That Scottish opinion, in a remarkable plurality, is not "legitimate"? If a Unionist fails to see the risk in that, he doesn't understand Union.

So: silly or stupid, or a bit of both? I could say, not for the first time, that either would suit me fine. The problem would be that Mr Miliband is still in with a shout to run this UK. It's not, or not yet, just a hill of beans. If luck is with him he could be making life-and-death decisions before the month is over. We already have Mr Cameron's measure where "the Scots" are concerned. So there's that charge: is either man, with those views, still fit to run a United Kingdom?

The SNP might like to consider the question. Ms Sturgeon's attitude to the Conservatives is as clear as her unambiguous attitude towards Trident: no means no. Good. But Mr Miliband's behaviour makes me wonder whether investing the idea of "influence" in him is beyond question. Brutally, do you ask perhaps half the voters in Scotland to help you prop up a person who treats Scottish voters as a nuisance?

Those who might still vote Labour here must despair this morning. In essence, this is about the Union and where we all stand now, in these islands. This is not, on paper or in practice, an election "about independence". A simple grasp of how the Commons works would tell you that there need be no crisis on May 8. A couple of leftish parties haggle a little and life - not to mention the British Establishment - goes on.

But Mr Miliband wants his gesture and his fight. To a huge number of Scottish voters, he becomes his own paraphrase: "Hell, no". The astonishing thing is that he, like Mr Cameron, seems not to understand how dangerous this is for all the things he claims to defend.

It's possible, of course, that we have been written off in more senses than we yet understand. That would explain a few things, some press coverage not least. But they never did ask what was in that auld sang. The leader of the Labour Party wouldn't know what on earth the remark means.