Following confidential negotiations over the summer of 1918, it was agreed that certain candidates were to be offered the support of the Prime Minister and the leader of the Conservative Party at the next general election. To these candidates a letter, known as the Coalition Coupon, was sent, indicating the government's endorsement of their candidacy. 159 Liberal, 364 Conservative, 20 National Democratic and Labour, and 2 Coalition Labour candidates received the coupon. For this reason, the election is often called the Coupon Election.