 Diefenbaker was also upset when Pearson was invited to the White House for a dinner for Nobel Prize winners in April, and met with the President privately for 40 minutes.When the Prime Minister met with retiring American Ambassador Livingston Merchant, he angrily disclosed the paper Kennedy had left behind, and hinted that he might make use of it in the upcoming election campaign.Merchant's report caused consternation in Washington, and the ambassador was sent back to see Diefenbaker again.