Heseltine, he was one of those 40 years ago who lied to the British public.
The lie at that time was that we were only joining the EEC as a trade organization. As the other major European nations were going to be doing this, The UK felt it should get in and become part of and maybe even defend or dominate - whatever.
That's how it was presented to the public and a referendum was put in which people affirmed they wanted to be part of that.
Maastricht and sundry other events such as Lisbon showed clearly though there had been no intention ever at leaving it at that. The Club of Rome was behind the whole push and that contained many of the worst elements of the German old family elite, the same ones who had enabled Hitler.
The Germans' purpose became clear - to dominate Europe and assist in the dismantling of the UK, in particular dismantling England as a unit and turning it into 9 regions of the EU, along with Scotland, Ireland and Wales.