General Election: Theresa May targets historic win for Tories in Wales

Theresa May is parking her tanks directly on Labour's lawn today as a shock poll suggests the Tories could take a majority of votes cast in Wales for the first time in more than 150 years.

The Prime Minister's arrival in South Wales follows her trip to Labour-held Bolton North East - the sort of constituency that, if it changed hands, would be indicative of a Tory landslide and a nightmare for Labour leader Jeremy Corbyn.

In both cases, while Labour is leaking some votes to the Conservatives (and to the Liberal Democrats), it is the boost to the Tories from former UKIP voters which has meant a further setback for the Opposition.

Mrs May's visit comes on the back of a surprise poll from YouGov suggesting the Conservatives could be set to gain the majority of votes in Wales for the first time since 1859 - and not by a slight margin, but a full 10 percentage points.

If that came to pass, it would be a crisis for Labour.

But what is new is not the weakness of Labour, but a peak for the Conservatives - with UKIP working as a waypoint between the parties.

Pollsters often caution to watch the vote share in a poll, not the lead. Labour's vote share is low - the lowest it has been since the nadir of Gordon Brown's premiership in 2009.

But it is not much down on where it was in January, when the company last polled Wales.

Rather, it is UKIP that has borne the brunt of the Conservative surge, down seven percentage points with the Tories up 12.

This is a very large swing from when they last asked the question just three months ago; you shouldn't read too much into any individual poll.

We should also bear in mind that the strength of UKIP was slightly over-represented in the polls ahead of the Welsh Assembly in 2016.

But the findings are remarkable. Even if they are as far out as the general election polls of 2015, it would still indicate the best result in Wales for the Tories in living memory.

And a similar phenomenon is consistently reflected in polls across the country.

If the Conservatives can repeat the trick nationwide - claiming a chunk of the vote from Labour, and a large slice of the diminishing UKIP vote - it could spell disaster for Labour on both sides of Offa's Dyke.