An astonishing new poll for the Cardiff University Governance Centre and ITV Cymru shows a historic result: the Conservatives ending a 167-year wait for an election victory in Wales.

The numbers that matter:

Conservatives: 40 per cent

Labour: 30 per cent

Plaid Cymru: 13 per cent

Liberal Democrats: 8 per cent

Ukip: 6 per cent

Others: 3 per cent

And for context, here’s what happened in 2015:

Labour 36.9 per cent

Conservatives 27.2 per cent

Ukip 13.6 per cent

Plaid Cymru 12.1 per cent

Liberal Democrat 6.5 per cent

Others 2.6 per cent

There’s a lot to note here. If repeated at a general election, this would mean Labour losing an election in Wales for the first time since the First World War. In addition to losing the popular vote, they would shed ten seats to the Tories.

We're talking about a far more significant reverse than merely losing the next election.

I don’t want to detract from how bad the Labour performance is in a vacuum – they have lost 6.9 per cent of their vote on 2015, in any case the worst election performance for Labour in Wales since the rout of 1983. But the really terrifying thing for Labour is not what is happening to their own vote, though that is pretty terrifying.

It’s what’s happened to the Conservative vote – growing in almost every direction. There is some direct Labour to Tory slippage. But the big problem is the longtime fear of Labour MPs – that voting for Ukip would be a gateway drug to voting for the mainstream right – appears to be being realised. Don't forget that most of the Ukip vote in Wales is drawn from people who voted Labour in 2010. (The unnoticed shift of the 2010-5 parliament in a lot of places was a big chunk of the Labour 2010 vote went to Ukip, but was replaced by a chunk of the 2010 Liberal Democrat vote.)

If repeated across the United Kingdom, the Tory landslide will be larger than the 114 majority suggested by the polls and a simple national swing.

As I’ve said before, polls are useful, but they are not the be-all and end-all. The bad news is that this very much supports the pattern at elections since the referendum – Labour falling back, the Tories losing some votes to the Liberal Democrats but more than making up the loss thanks to the collapse of Ukip.

The word from Welsh Labour is that these figures “look about right” at least as far as the drop in the Labour vote, though of course they have no idea what is going on with their opponents’ vote share. As for the Conservatives, their early experiences on the doorstep do show the Ukip vote collapsing to their benefit.

One Labour MP said to me a few days again that they knew their vote was holding up – what they didn’t know was what was happening to their opponents. That’s particularly significant if you have a “safe seat” but less than 50 per cent of the vote.

Wales has local elections throughout the country on 4 May. They should provide an early sign whether these world-shaking figures are really true.