It is the most keenly awaited polling exercise I can remember, so what does it tell us? Basically, the same as all other recent Scottish surveys.

Does that mean that Lord Ashcroft’s bumper pack of 16 single-seat polls are a bit of a yawn? Not at all, because what all the available evidence has been telling us for months – and what Wednesday’s surveys confirm in spectacular fashion – is that something truly seismic has happened to Scotland’s politics since September’s referendum.

A total of 16 surveys of nationwide Scottish voting intentions have been logged at UK Polling Report since the referendum vote. Ashcroft’s new polls at a stroke double the volume of Scottish data. They’ve interviewed 16,000 people, and – furthermore – have done so over the phone, which most analysts still think enjoys the edge for accuracy over increasingly common internet surveys.

Last but not least, by conducting separate surveys in individual seats, the Conservative peer pulls away the comfort blanket from any Labour or Liberal Democrat MP who was imagined that the extraordinary swing to the SNP, which nationwide polls have been showing, is something that is happening somewhere other than their own back yard.

The mainly working-class cities of Glasgow and Dundee voted yes to independence in September, and the perception is very much that it is in such areas that the sharpest swing to the SNP is now being found. In our own Christmas survey with ICM, we drilled down into the data with Prof John Curtice and established that the swing from Labour to the SNP was actually most pronounced in Labour supposed heartland seats.

Now Ashcroft has concentrated his examination of the SNP surge in those old socialist citadels that were most inclined to side with independence last year. Just for fun, he thought he’d also commission a couple of costly polls to confirm that Alex Salmond is on his way back to parliament, and Danny Alexander is on his way out, but the real focus of the exercise was very much on the Labour/SNP battleground.

And the results could hardly have been more dramatic. The SNP are on course to clean up in 15 of the 16 seats surveyed, often by double-digit margins. Glasgow Central, North, North-West and South-West all go. Only the North-Eastern constituency in the UK’s third-most populous city would remain loyal to Labour, according to these polls.

The polls’ reliability is confirmed by their consistency – the average swing in the Labour-held seats was closely bunched around the average of 25%, never more than 27% but never less than a still-pretty spectacular 21%. In a cautious write-up, Ashcroft acknowledges that the nationwide swing would be expected to be somewhat smaller, since the SNP are probably surging less strongly in places that voted no.

That can hardly be relied on to save Labour’s bacon however, since in these places Labour’s majorities are smaller to start off with – so a smaller swing w be enough to wipe them out. The only real glimmer of hope for Ed Miliband and Jim Murphy, leader of the Scottish arm of the party, is that only two-thirds of Labour defectors indicate that their mind is now completely made up – implying one in three could still change their minds.

A strong campaign reminding people that a smaller Labour party in parliament will make it easier for David Cameron to remain in No 10 might just pull many of these SNP flirters back to the Labour fold. And that might, perhaps, make the difference between Labour remaining in business in significant parts of its heartlands, and being wiped out. But with just three months until polling day, it is hardly enough for the party to come back and win. It looks very much like Labour’s Scottish election is lost – unless something important changes between now and election day.

For the Liberal Democrats, the data in these polls is less exhaustive – but it is, if anything, bleaker. Scotland is the only part of the UK where the electoral system has not disadvantaged them in recent years – their vote share in 2010 was very much in line with their clutch of 11 Scottish seats. These polls confirm they have been practically eliminated as a Scottish force.

In the Labour-held seats, Nick Clegg’s party is running on scores that can be counted on the fingers of one hand – 4, 3, 2 and in several cases 1%. One of the safest Lib Dem seats last time was Danny Alexander’s huge highland turf of Inverness, Nairn, Badenoch and Strathspey, but Ashcroft’s data suggests that the chief secretary to the Treasury is not merely on course to lose, but to go down by a humiliating margin of 29 points, as the SNP surge to 50% of the vote. One can’t be certain whether his popular, and anti-coalition, political neighbour, Charles Kennedy in Ross, Skye and Lochbar – would suffer the same fate.

A strong personal vote could just save Alexander: perhaps Ashcroft will do a separate poll there to check. But in the meantime, aside from Kennedy, this latest data gives credence to the possibility that the Liberal Democrats will be entirely wiped out from mainland Scotland, and be consigned to Orkney and Shetland, the one seat they really can’t lose.

It would have seemed unimaginable in 2010; but as early as 2011 it had already happened in SNP landslide at Holyrood – in the constituency contests, the Lib Dems could only hold on in these islands. Anyone who still doubts the polls, should remember that Scotland has already given all the Westminster parties the boot at the ballot box once. It now looks poised to do the same thing in elections to Westminster itself.

This article was written by Tom Clark, for on Wednesday 4th February 2015 11.10 Europe/London © Guardian News and Media Limited 2010