The fact that in the 2016 Europe referendum two nations of the UK voted to leave, two nations voted to remain, inevitably makes this a very difficult, delicate process.

I think that with good will and a good deal, those tensions can be handled, but I think that the risk of no-deal is two-fold.

I believe a no-deal outcome would do very serious harm to jobs, living standards and investment in the United Kingdom, and that is the consistent message I've been getting from businesses large and small.

But also I think the pressures on the union would be greater because I think that damage that a no-deal exit would cause, the very divisive nature of the politics of such an outcome, would give heart and opportunities to those who, particularly in Scotland and in Northern Ireland, would like to see the United Kingdom as it currently exists brought to an end.