North Sea oil expansion is a necessity (Burnham risks first revolt as PM over apparent support for North Sea drilling, 31 July). Hence oil is part and parcel of supply chains for green tech. A major expansion of the UK’s North Sea oil sector will make a more cohesive UK, complete with more jobs in Scotland and the north of England, including in supply manufacturing chains. On these grounds, the full approval of North Sea oil expansion is an absolute litmus test of Andy Burnham’s credibility given his talk of reindustrialising. John BarstowFittleworth, West SussexBurnham’s avowed pragmatism appears to be disappointingly deficient as far as North Sea oil is concerned.