During WW2, Britain amassed a debt of billions of dollars, liberating those who now are bent on destroying a once prosperous nation. Taking into account the rebuilding, by the mid-sixties, Britain were heading for bankruptcy. By 1969, the only option was to join the EU, to ensure more economic stability. And so, on the 1st of January, 1973, Britain became part of the EU. Since that time, the EU have been screwing Britain for every last drop of blood, for no other reason than to support the weaker countries; Britain, being one of the highest contributors, can no longer sustain a support role for those countries that seem unable to help themselves, and not before time, are calling it a day.
It seems that Merkel and Macron are running the show, although how the German Chancellor and a washed-up politician who can't keep the population of his own country under control are allowed to dictate such terms, I don't know. One thing for sure, the EU will make it as hard as possible for Britain to leave, as a warning to any other country having similar ideas.
Most of the EU countries appear to have short memories. The demise of the EU will not be too far off once Britain leaves, and those countries with "similar ideas" won't be too far behind.