Margaret Thatcher warned Parliament way back in 1990.  She had the foresight to see that turning over British sovereignty to Europe and giving up the pound in favor of a common currency would be disastrous.  Here are a couple of excerpts from her 1990 speech to the House of Commons:

The president of the commission, Mr. Delors, said at press conference the other day that he wanted the European Parliament to be the democratic body of the community. He wanted the commission to be the executive and he wanted the Council of Ministers to be the Senate. No. No. No.

Perhaps the Labor Party would give all those things up, easily. Perhaps they would agree to a single currency, to total abolition of the pound sterling. Perhaps being totally incompetent with monetary matters they’d be only too delighted to hand over the full responsibility as they did to the IMF, to a central bank. The fact is, they have no competence on money, no competence on the economy, so, yes, the right honorable gentleman would be glad to hand it all over. And what is the point? In trying to get elected to Parliament only to hand over your sterling and to hand over the powers of this house to Europe.

And the video:

In 2002, Thatcher wrote a book entitled “Statecraft”.  Thatcher was still insisting that Great Britain should handle it’s own affairs.

Great Britain was once more contemplating joining Europe to form one government, which prompted Thatcher to conclude:

“that such an unnecessary and irrational project as building a European superstate was ever embarked upon will seem in future years to be perhaps the greatest folly of the modern era.”