He was the son of Susan (née Collins) and Warren Marwick, a farmer who was elected to the Western Australian Legislative Council in 1910.

He was a strong advocate for primary producers and supporter of states' rights, and publicly criticised the Commonwealth Grants Commission as biased against Western Australia.

[1] He was defeated after a single term at the 1943 election by the Australian Labor Party (ALP) candidate Don Mountjoy.

[3] He was endorsed by the Country Party as a candidate for the 1944 Swan state by-election, but withdrew in favour of Hurtle Prater who was defeated.

He died at St John of God Subiaco Hospital on 3 April 1960, aged 64, having retired from farming ten years earlier.