However, the Leave campaign and all who sail in her need to
Even if the £66bn cost to the treasury of Brexit is true, and in my opinion it is a serious underestimate, the country will be in financial trouble. If we leave the EU in a hard Brexit unemployment will rise and keep rising for some time, businesses will go bankrupt, incomes will fall and public services will be starved of cash. The £350 million a week promised to the NHS will, most likely, turn into a cut of at least twice that amount. Waiting lists will soar and people will spend hours lying on stretchers and trollies in A&E.
When this happens the popularity of Brexit and those who have most loudly advocated it will fall significantly, and there will eventually be a clamour for rejoining the EU, by invoking Article 49. As a way of rescuing the situation re-entering the EU will not be a panacea; by that time many industries will have left and persuading them to return will be fruitless. Why would Nissan want to move back to Sunderland after just building a new factory in Spain or Belgium? However rejoining will represent the only route back to prosperity.
The EU however is not going to want Britain back under any circumstances; there will be conditions attached, we would probably need to join the Euro, be part of the Schengen free travel zone and agree to something like a 66% majority in any future referendum on leaving. In other words Britain would be more securely embedded within the EU than it is now, and, if you think leaving is complex and difficult now, just imagine how difficult it would be if we are in the Eurozone.
The truth is that, even if Brexit goes ahead, the pressure to rejoin will not go away, especially as living standards fall significantly. The number of Rejoiners will increase and the result will eventually be a "Hard Rejoin" with Leavers campaigners marginalised, discredited and blamed for the economic disaster which will hit those who voted Leave in the greatest numbers.