In the early 1990s, when John Major was at war with his party over Europe, there was one issue on which, broadly speaking, he found common ground with the Euroskeptics. It was EU enlargement. Supporting expansion to incorporate the former communist nations of central and eastern Europe was the golden scenario.

"Wider rather than deeper" was the catchphrase. By expanding eastwards — so the Tories believed — the European Union would become so big that political union would be impossible. A bigger EU would evolve into a looser union of free trading nation states, with weaker institutions at its center. It was the way to put the brake on Franco-German and Benelux ambitions for ever-closer union, while widening the internal market and promoting stability between east and west. The vision of Europe that Margaret Thatcher had outlined in her 1998 Bruges speech would come into being.

In 2002, Tory European Parliament member Roger Helmer, who went on to defect to the U.K. Independence PArty (UKIP), put it like this: "Tory policy on enlargement is clear. We are in favor of it, for three reasons. First, we owe a moral debt to the countries of central and eastern Europe, which were allowed to fall under the pall of communism after the Second World War. Second, by entrenching democracy and the rule of law in eastern Europe, we ensure stability and security for the future. Third, an extra 100 million people in our single market may be a short-term liability, but long term will contribute to growth and prosperity."