 In 1980, he was elected to the Australian House of Representatives as the Labor member for McMillan, defeating Barry Simon of the Liberal Party, who had been deprived of Democratic Labor Party preferences due to his views on abortion.He was defeated in 1990, but was re-elected in 1993, before being defeated again in 1996.In 2015, Cunningham and three other former MPs brought a case before the High Court of Australia, purporting that reductions to their retirement allowances and limitations on the number of "domestic return trips per year" under the Members of Parliament (Life Gold Pass) Act 2002 was unconstitutional under S51(xxxi) of the Constitution of Australia.