Edward Heath: The fanatics in the Conservative Party risk everything we have gained

It is now more than 30 years since I steered this country towards membership of the European Economic Community (EEC), as it was then called. I look back with great pleasure and nostalgia at my proudest political achievement. However, I do so with a strange sense of déjà vu, for, all that time later, the debate about our relationship with Europe still rumbles on.

I have been a committed European since my Oxford days; my pro-European outlook was reinforced by my wartime experiences. In 1945, as the victors and the vanquished surveyed the devastation wrought upon the continent, it became obvious to the peoples of Europe that their continent could not afford another war. Together they decided to build a Europe in which all of its people could see and share in the benefits of democracy and economic and political freedom.

When I entered the House of Commons in 1950 it was clear to me, and my party leader, Winston Churchill, that our country's future lay in playing a prominent role in the development of a common European home. Unfortunately, while six European countries were actively negotiating to create a European Community based on shared laws and interests, Britain stood aside in a doomed attempt to relive past imperial glories and thus lost the opportunity to be a founder member of that community. However, its architects, Jean Monnet and Robert Schuman, correctly recognised that the European Community would not be complete without the United Kingdom.

By the 1960s the decline of Britain's economic power at home and its political influence abroad, particularly in the wake of the Suez crisis, necessitated a reappraisal of its relationship with Europe. Harold Macmillan quickly recognised the truth that Britain's economic and political interests lay in Europe, but sadly the application was rebuffed by the French President, Charles de Gaulle. So when I became Prime Minister I was determined to take this country into the EEC.

I knew that it was the only serious policy available to halt our economic and political decline. Before we joined, our decline as a global industrial power had not been gentle, but chronic and accelerating. The six were reaping enormous gains from the community, while we missed out. Indeed, during the 15 years of our isolation, and despite extensive wartime devastation, German and French productivity overtook Britain's.

Of course, there were many who disagreed and some, especially in the Labour Party, did so for purely partisan political reasons. Thankfully there were enough members of the House of Commons, the majority Conservatives, but Labour members too, who fought successfully to ensure that our future was a European one.

Some 30 years on, we have a good vantage point from which to assess the consequences of this decision for Britain. Our country is stronger – politically and economically – more prosperous, and more influential as a consequence.

Following the years of decline, joining the EEC was a form of shock treatment. The cosy, and ultimately debilitating, trading regimes inherited from the days of imperial preference and state subsidy were removed, and industry faced more competition than ever before. In return we had the opportunity to export into new and growing markets. And with that came a new attractiveness for Britain as a destination for inward investment.

As with all shock therapies the going was tough. It was 10 or more years before investment and competition began to turn around some of our manufacturers and made our steel industry one of the best in the world. Today, more than half of our trade is with the European Union, and that trade sustains at least 3.5 million jobs. Tens of thousands of foreign investors have chosen Britain as a base from which to export to Europe.

Today no serious business figure would disagree that Britain is better off in Europe, and these days even most trade unionists, and the Labour Party, are in favour. In the modern world it is only right and sensible that we should share our sovereignty with our European neighbours for the greater benefit of all. Those who claim that this country could go it alone and still continue to "punch above its weight", as they put it, are doing the United Kingdom a great disservice. We might be able to survive economically, but the loss of influence on the world stage would be huge. This country would become increasingly marginalised in world affairs. Unfortunately there are still those who continue to oppose our membership of the European Union. These fanatical opponents will never give up. They had two bites at the cherry in the 1970s and lost. They had a wealthy man fund the Referendum Party and lost. They staged a coup in the Conservative Party and again were rejected by the electorate.

Now they are focusing their attention on the euro. It is my view that if we are serious about our future in Europe, and particularly the single market, then we will have to join the euro. Many of the benefits of the past 30 years will be at risk if we do not. We cannot be half in the single market and half out. We cannot be half in Europe and half out. For the second time in a quarter of a century the British people are going to be asked to vote on whether or not this country can remain a committed player in Europe. A "no" vote will permanently relegate us to the second division of European nations. I look forward to campaigning vigorously for a "yes" vote.

Once this question is decided perhaps we can finally settle ourselves into being a major European player – the path on which I set our country all those years ago.

Sir Edward Heath was Conservative prime minister from 1970-74. The United Kingdom joined the European Community under his leadership in 1973.