Although Brexit is still a work in progress, Kevin O'Rourke, Professor of Economic History at Oxford University, has written a book on the subject called A Short History of Brexit: From Brentry to Backstop.
As Kevin explains, many people don't fully understand what being part of the European Union is all about, and Brexit will result in "major costs for the British economy."
He says the British want to "have their cake and eat it — they never really wanted to be in a position where they had to choose between Europe and the Commonwealth", which they could have done had the original six EEC member states gone with the free trade area rather than a customs union with a common external trade policy.
Kevin says the Tory party is split between "a pragmatic wing who want to continue to trade in a frictionless manner with the rest of Europe, and a bunch of people whose priority is to regain sovereignty."
"You can't actually do both of those things simultaneously, so they will have to choose, but that's proving terribly difficult for them."