'It is hard to predict how full Brexit would play out, because this scale of multiple simultaneous renegotiations of global trade agreements is unprecedented – and no country has ever left the EU. It certainly can’t be assumed that Britain is bound to get quick and good deals because it is a large economy.'

With negotiations between the UK and the European Union (EU) - over a trade agreement - going down to the wire, the possibility of there being no deal is being talked about.