“Accession to the Treaty of Rome would not involve a one-sided surrender of ‘sovereignty’ on our part, but a pooling of sovereignty by all concerned, mainly in economic and social fields.
“In renouncing some of our own sovereignty we would receive in return a share of the sovereignty renounced by other members.”
 ▪ SIR ALEC DOUGLAS-HOME: Mr Macmillan’s successor, Sir Alec Douglas-Home, was briefly prime minister for one year from 1963. He supported Britain’s application to join the European Community, although Harold Macmillan’s application had been vetoed by the French President, Charles de Gaulle.

 In his party’s manifesto for the general election of 1964, Sir Alec stated:
“We remain convinced that the political and economic problems of the West can best be solved by an Atlantic partnership between America and a united Europe. Only in this way can Europe develop the wealth and power, and play the part in aiding others, to which her resources and history point the way.”
Later, as Foreign Secretary in Edward Heath’s government that took Britain into the European  Community, Sir Alec said in a speech in Parliament in June 1971 on the importance of the United Kingdom’s membership:
“I think the time has come when we must say to the public in our country that the future prospect ahead of us is uncertain unless we can expand our markets and unless we can become part of a bigger organisation; for trade, for investment, and also for political reasons.”
The following month in Parliament he said:
“I have never made it a secret that I cannot see an alternative which would offer as good a prospect for this country as joining the E.E.C. [European Community].”
And he also stated:
“I, too, have concluded through the years that membership of the Community would be advantageous to Britain.”
 ▪ EDWARD HEATH: It was Conservative Prime Minister, Edward Heath, who joined Britain to the European Community on 1 January 1973, following the backing of Parliament after 300 hours of debate.

 On the evening of 28 October 1971, Mr Heath addressed the House of Commons during the momentous debate on Britain joining the European Community. He said:
“Surely we must consider the consequences of staying out. We cannot delude ourselves that an early chance would be given us to take the decision again.
“We should be denying ourselves and succeeding generations the opportunities which are available to us in so many spheres; opportunities which we ourselves in this country have to seize.
 “We should be leaving so many aspects of matters affecting our daily lives to be settled outside our own influence. That surely cannot be acceptable to us.
“We should be denying to Europe, also – let us look outside these shores for a moment – its full potential, its opportunities of developing economically and politically, maintaining its security, and securing for all its people a higher standard of prosperity.”
 Mr Heath added:
“..tonight when this House endorses this Motion many millions of people right across the world will rejoice that we have taken our rightful place in a truly United Europe.”
Parliament did endorse the Motion by 356 votes to 244, and Britain subsequently joined the European Economic Community on 1 January 1973.
▪ MARGARET THATCHER: Two years later, in 1975, the Labour government offered the British people a referendum on whether the country should remain in the European Community. Tory leader and future Prime Minister, Margaret Thatcher, strongly campaigned for the country to remain in the Community.
In a speech in Parliament on 8 April 1975 supporting Britain’s continued membership of the European Community, Mrs Thatcher said:
“Membership of the Community enhances our effective sovereignty by giving the British Government increased influence and bargaining strength.”
She added:
“That is what sovereignty in the modern world is really about and that is why Britain is stronger inside the Community than she would be outside it.”
 And of pertinence to today, Mrs Thatcher said:
“If we were now to withdraw, it would be a leap in the dark. We should not have any idea of the trading conditions into which we were coming out or of the effect on sterling.”
In another keynote speech on 16 April 1975 during the referendum campaign she said:
“It is not surprising that I, as Leader of the Conservative Party, should wish to give my wholehearted support to this campaign, for the Conservative Party has been pursuing the European vision almost as long as we have existed as a Party.”
 As Prime Minister, Mrs Thatcher also pushed for, and made possible, the Single Market of Europe. In September 1988 in Bruges, Mrs Thatcher gave a major speech about the future of Europe. She said:

“Britain does not dream of some cosy, isolated existence on the fringes of the European Community. Our destiny is in Europe, as part of the Community.”
Mrs Thatcher added:
“Let Europe be a family of nations, understanding each other better, appreciating each other more, doing more together but relishing our national identity no less than our common European endeavour.”
Crucially she said in support of the Single Market:
“By getting rid of barriers, by making it possible for companies to operate on a European scale, we can best compete with the United States, Japan and other new economic powers emerging in Asia and elsewhere.”
▪ JOHN MAJOR: It was former Conservative Prime Minister, John Major, who negotiated and won Parliament’s backing to sign the Maastricht Treaty, that among other benefits gave us EU Citizenship rights allowing us to reside, work, study or retire across a huge expanse of our continent.
He called for Britain to be at ‘the very heart of Europe’.
At the Tory Party Conference of 1992, just six months after John Major won a surprise victory that year in the General Election, he said to the party faithful:
“I speak as one who believes Britain’s future lies with Europe.”
And Mr Major warned about Britain walking away from Europe:
“We would be breaking Britain’s future influence in Europe. We would be ending for ever our hopes of building the kind of Europe that we want. And we would be doing that, just when across Europe the argument is coming our way. We would be leaving European policy to the French and the Germans.
“That is not a policy for Great Britain. It would be an historic mistake. And not one your Government is going to make.”
And Mr Major crucially added:
“Let us not forget why we joined the Community. It has given us jobs. New markets. New horizons.
“Nearly 60 per cent of our trade is now with our partners. It is the single most important factor in attracting a tide of Japanese and American investment to our shores, providing jobs for our people..
“But the most far-reaching, the most profound reason for working together in Europe I leave till last. It is peace. The peace and stability of a continent, ravaged by total war twice in this century.”
▪ DAVID CAMERON: Theresa May’s predecessor, Conservative Prime Minister, David Cameron, also strongly supported Britain’s continued membership of the EU, and his government’s official advice to the electorate during the Referendum was to vote for Remain.
In a speech on 9 May 2016 in support of the UK remaining in the EU during the referendum campaign, Mr Cameron said:
“I believe that, despite its faults and its frustrations, the United Kingdom is stronger, safer and better off by remaining a member of the European Union.”