Lower wages and perceptions of profiteering by some businesses led, in 1916, to a wave of strikes by miners, waterside workers and shearers. Enlistments also declined, falling from 35,000 a month at its peak in 1915 to 6,000 a month in 1916. Hughes returned from a trip to England and the Western Front in July 1916 and narrowly won a Cabinet vote to hold a referendum on conscription for overseas service. In September the New South Wales Labor Party expelled Hughes on account of the issue. Following the narrow defeat of the October 1916 conscription referendum, the state branches of the Labor party began expelling other prominent pro-conscriptionists. In November, Hughes and 23 of his supporters left the parliamentary party, and in January 1917 they formed a new Nationalist government with the former opposition. The Nationalists comfortably won the May 1917 elections and Hughes continued as prime minister. Political and industrial unrest intensified in 1917. From August to October there was a major strike of New South Wales railway, transport, waterside and coal workers which was defeated after the Commonwealth and New South Wales governments arrested strike leaders and organised special constables and non-union labour. The Industrial Workers of the World (IWW) was declared an unlawful organisation and more than 100 of its members were arrested. In September, protests by the Women's Peace Army in Melbourne resulted in extensive damage to shops and offices. Following further falls in enlistments in 1917, Hughes announced a second referendum on conscription to be held in December. The referendum campaign proved divisive, with Hughes denouncing opponents of the measure as "the Germans of Australia, the Sinn Féin and the IWW." The Catholic Archbishop of Melbourne, Daniel Mannix, and the Labor premier of Queensland T. J. Ryan were prominent campaigners against conscription. The referendum was defeated by a wider margin than in 1916. An April 1918 recruiting conference including representatives of the Commonwealth government, State governments, employers and labour leaders also failed to reach agreement on measures to increase troop numbers. Enlistments in 1918 were the lowest for the war, leading to the disbandment of 12 battalions and mutinies in the AIF. Paris peace conference Hughes attended the Imperial War Conference and Imperial War Cabinet in London from June 1918 where Australia, New Zealand, Canada and South Africa won British support for their separate representation at the eventual peace conference. At the Paris Peace Conference