According to a report by Oliver Wyman management consultants and law firm Clifford Chance

They say that firms in the EU's 27 countries will have to pay £31 billion a year in tariff and non-tariff barriers if the UK leaves the European bloc without a deal, and in return, UK exporters to the EU will have to pay £27 billion a year.

The report says that "these increased costs and uncertainty threaten to reduce profitability and pose existential threats to some businesses" and that in an absence of an agreement, trade between the UK and the other EU 27 members would default to World Trade Organisation rules and tariffs.

A key point to highlight from the report is that 70% of the extra costs in the UK will be shared across just five industries - namely financial services, cars, agriculture and food and drink, consumer goods, and chemicals and plastics. The biggest hit sector is of no surprise, and that is financial services.

In the past week, we've already started to see some some financial firms start to take action in case of such contingencies - with Goldman Sachs and UBS deciding to shift some of their staff to Frankfurt.