Pitt's relationship with the Duke slumped further in early 1756 when he alleged that Newcastle was deliberately leaving the island of Menorca ill-defended so that the French would seize it, and Newcastle could use its loss to prove that Britain was not able to fight a war against France and sue for peace. When in June 1756 Menorca fell after a failed attempt by Admiral Byng to relieve it, Pitt's allegations fueled the public anger against Newcastle, leading him to be attacked by a mob in Greenwich. The loss of Menorca shattered public faith in Newcastle, and forced him to step down as Prime Minister in November 1756.