The Labour government of Harold Wilson sent every voter a pamphlet advising us to vote to stay in the EEC. A crucial promise was made
”There was a threat to employment in Britain from the movement in the Common Market towards an Economic and Monetary Union. This could have forced us to accept fixed exchange rates for the pound, restricting industrial growth and so putting jobs at risk . This threat has been removed”
Well it was not. As they rightly forecast EMU would destroy jobs which is what happened when the UK was pushed into it by all 3 main parties.
The tract also assured us we would not lose our Parliamentary sovereignty. It said
”It is the Council of Ministers who take the important decisions…The Minister representing Britain can veto any new law or tax if he considers it to be against British interests”
Instead the EEC/EU went over to qualified majority votes where we could be ignored or overridden.