[3] Salter then joined Monnet at the League of Nations Secretariat in Geneva, as head of the Economic and Financial Section, where he was involved in the stabilization of currencies of Austria and Hungary and resettlement of refugees in Greece and Bulgaria.

In his book, he also set out a template remarkably similar to that adopted by his former colleague Jean Monnet for the structure of the European Economic Community (EEC) in 1957.

To that extent, Salter is regarded by some as co-author, with Jean Monnet, of the supranational structure of what became the European Union.

In June 1940, he once more supported Jean Monnet on the short-lived Franco-British Union proposal to politically unify Britain and France as a bastion against Nazism.

Later, Salter headed the British shipping mission to Washington from 1941 to 1943, where he employed Monnet and they worked together on what would become the Victory Program of military industrial buildup.

Churchill offered him a new economic department in the Conservative Government formed that November, but he decided to join the Treasury provided he had access to the Cabinet.

[7] Butler's biographer Anthony Howard writes that Salter was "never more than a minor, and sometimes visible, irritant to the new Chancellor".