THIS is about as febrile as it gets in British politics.

Forget the recent hyperbolic anti-Scots rhetoric of John Major and Boris Johnson. Or the curious serenity underlying the bustling crowds, flags and selfies of the SNP campaign. Look at where criticism of the major parties is coming from, and the desperate tactics being resorted to.

To take the latter first, what can we say about the breathtaking effrontery and highly dubious ethics of Danny Alexander? As the Chief Secretary to the Treasury for five years he sat not just in the Cabinet, bound by collective responsibility, but on the Quad, comprising the Prime Minister, the Chancellor, Nick Clegg and himself.

Mr Alexander - one assumes this act of treachery now precludes him from becoming Lord Alexander - commissioned a report on benefit cut options from Iain Duncan Smith whose suggestions were draconian, particularly on Child Benefit, but were rejected. Three years later, just as he is facing being ousted by his Highland constituents in favour of the SNP, he "leaks" the "Secret Tory Plans" discussed and rejected in Cabinet. He may be impressing the actor Hugh Grant but it all smacks of desperation and dishonesty. The party's Scottish leader Willie Rennie is soldiering on; yesterday he was making mince in a farm shop, today it's an event involving therapy pets. We'll let these speak for themselves.

The Conservatives really need to listen to Lord Ashcroft, who does not just accumulate polling data but draws increasingly astute findings from them. Have Labour learned their lessons and proved they can be trusted on the economy? He told a meeting in Edinburgh: "They have not so much failed their test as refused to hand in their homework." On his own party, he is convinced they have yet to shed the impression that they are the nasty party who cannot be trusted with the public services.

He believes David Cameron is an asset as a credible leader but, without naming him, Ashcroft clearly has doubts about Australian strategist Lynton Crosbie.

"It seems to me that if one of your problems as a party is that some of the voters you need think you are 'nasty', then launching personal attacks against your opponent is not the best way to capitalise on one of the few advantages you have," he said.

The fomenting of cross-Border animus is also hampering the Tory campaign North of the Border, as a former party communications chief pointed out this week, but Ashcroft is more optimistic that in time, when Scotland has more control over and responsibility for its finances, his party, under Ruth Davidson, can make a comeback.

Both the main Westminster parties have campaigns which reinforce views without changing them, Ashcroft argues. So the Tories continue with competence and leadership and Labour talk about the NHS, leaving UK polls deadlocked.

Responding to the threat of Ukip has brought out the Tories' nasty streak again and much of that has been aimed at the Scots as a way of undermining Labour and the prospect of any deal with the SNP. They, in turn are praised by Lord Ashcroft for their "powerful and attractive leader" and for the focus of their message of a strong voice for Scotland at Westminster applying corrective pressure on Labour.

As for Labour, Jim Murphy soldiers on, as he must, but the headline on an article on the politics.co.uk website this week said it all: "Has any Labour leader ever run a worse campaign than Jim Murphy?" Categorising the campaign as complacent, uninspiring, counterproductive and purely negative, the article said: "It's usually best to wait until a victim is declared dead before beginning the autopsy. However when it comes to the Scottish Labour Party, it seems wise to get our latex gloves on now."

It is getting late to turn the tide now, but Labour won 15 constituency seats at the last Scottish Parliament election so anything approaching that would be a blessed relief from the near-wipe-out which as of now seems more likely.