Conservative Ben Houchen will be the first mayor of the Tees Valley, made up of heartland Labour territory across Darlington, Hartlepool, Middlesbrough, Redcar and Cleveland, and Stockton-on-Tees. The average disposable income per capita across the area is £14,888. The Tories will now be looking very hard at constituencies like Middlesborough South (was Tom Blenkinsop’s but he is standing down) and Darlington (was Jenny Champan’s) at the general election. Labour yet to respond…