He was a Labor member of the New South Wales Legislative Assembly, representing Yaralla from 1978 to 1981 and Ryde from 1981 to 1988.
The son of Charles Victor and Leila Josephine McIlwaine, he was born in Concord West in Sydney.
He attended school in the Concord area and studied law part-time at the University of Sydney, completing the course in 1969.
[1] In 1978, McIlwaine was selected as the Labor candidate for the marginal Liberal seat of Yaralla, and he defeated the sitting MP, Lerryn Mutton.
[2][3] Subsequent to his defeat, he held the position of Judicial Registrar of the Federal Court of Australia (1997–98).