The introduction of conscription by the Australian government in response to a worsening regional strategic outlook during the war was consistently opposed by the ALP and by many sections of society, and some groups resisted the call to military service by burning the letters notifying them of their conscription, which was punishable by a monetary fine, or incited young men to deliberately not register for the draft, which was punishable by imprisonment. Growing public uneasiness about the death toll was fuelled by a series of highly publicised arrests of conscientious objectors, and exacerbated by revelations of atrocities committed against Vietnamese civilians, leading to a rapid increase in domestic opposition to the war between 1967 and 1970. Following the 1969 federal election, which Labor lost again but with a much reduced margin, public debate about Vietnam was increasingly dominated by those opposed to government policy. On 8 May 1970, moratorium marches were held in major Australian cities to coincide with the marches in the US. The demonstration in Melbourne, led by future deputy prime minister Jim Cairns, was supported by an estimated 100,000 people. Across Australia, it was estimated that 200,000 people were involved.