As GM looks to sell its European operations to PSA, the UK government is between a rock and hard place as overseas companies look to ditch businesses or move investment decisions elsewhere - both of which could be adversely affected by Brexit. 

Nissan got in early for assurances which everyone assumes do not fall foul of State aid rules. The devaluation of sterling and pension changes voted through by the employees have also saved Tata Steel in Wales for the time being, but if things change expect the pressure on government to force action.

Did the UK make promises to PSA? If so expect a flood of overseas businesses with Brexit strained UK businesses at Greg Clark's door by the summer. Where will the line be drawn? The government's industrial policy looks strained already.