The country's problems were augmented by the First League of Armed Neutrality, which was formed to counter the British blockade strategy, and threatened British naval supplies from the Baltic. With severe manpower shortages, North's government passed an act abandoning previous statutes placing restrictions on Catholics serving in the military. This provoked an upsurge of anti-Catholic feelings and the formation of the Protestant Association that led to the Gordon Riots in London in June 1780. For around a week, the city was in the control of the mob until the military was called out and martial law imposed. Public opinion, especially in middle-class and elite circles, repudiated anti-Catholicism and violence, and rallied behind the North government. Demands were made for a London police force.