The Conservatives must never have any part in Farage's populist extremism Michael Heseltine

At the start of the second world war, President Roosevelt was forced by his Republican opponents to agree that America would not enter it.

- Michael Heseltine

Hitler then made the unbelievable mistake of challenging America's sovereignty by attacking the convoys upon which we depended before they reached the open sea. I have been privileged to live since then within the safety and security of the Pax Americana that one president after another has sustained since they helped to secure victory in 1945.

The United Nations with its wide spread of social and cultural agencies; Marshall Aid to help fund the postwar rebuilding of Europe; and the Nato alliance to ensure it could not happen again - I gave a speech in tribute to all this in 1986 called An Alliance not an Empire.

There are other uncomfortable memories from the end of the 1930s. The rise of fascism found its followers from the top to the bottom of European societies in Germany, Italy and Spain, while Oswald Mosley marched his followers through London's East End. It required Churchill's iron determination to stop his Conservative colleagues seeking peace with Hitler.

When the second world war ended, the abiding view was that it must never be allowed to happen again. Jean Monnet and Robert Schuman - the latter would become French prime minister - were among the most influential Europeans who created the European Coal and Steel Community. Churchill articulated the idea: “We must create a kind of United States of Europe.” Note his words; he said “we” not “they”.