The letters were all dated 20 November 1918 and were signed by Prime Minister David Lloyd George for the Coalition Liberals and Bonar Law, the leader of the Conservative Party.
The name "coupon" was coined by Liberal leader H. H. Asquith, disparagingly using the jargon of rationing with which people were familiar in the context of wartime shortages.
As Margaret Cole's memoir of the time makes clear, many competent and patriotic candidates who did not receive the coupon, including sitting Liberal and Labour MPs, found themselves categorised as somehow anti-war or pacifist as a result.
[6] Percy Harris, who had been MP for Harborough since 1916, recorded that once the coupon had been allocated to his Conservative opponent it was interpreted as a personal reflection upon him by his constituents who assumed he must have done something wrong for the Liberal Prime Minister to be seen offering his open support to a rival.
Those Liberals that Lloyd George chose to abandon were left defenceless against Coalition candidates, who had a full claim on the spirit of national unity and patriotism that characterised Britain's war weary mood following the end of hostilities.