It should come as no surprise to see David Cameron and George Osborne back in the north of England today. This is why:

The Tories are eyeing a total of 28 seats across the region. Even if they manage to pick up only half of these, a similar number of gains in the south-west – the party’s other main battleground – would see the Tories well on the way towards forming a majority government.

But northern England is also an area of great vulnerability for the party:

As much as the region could be the making of the Tories’ election chances, it could also be their breaking. A majority of these marginal seats are Labour targets. Expect to see David Cameron back in this part of the country many more times before polling day – and to hear that excruciating bit of jargon “northern powerhouse” unleashed at every opportunity.