He served as a government minister under James Scullin, John Curtin, Frank Forde, and Ben Chifley.

He became an official of the Boot Trade Employees Association, and was also active in the Australian Labor Party.

[1] At the 1928 federal election, Holloway stood as the Labor candidate against the Nationalist (conservative) Prime Minister Stanley Bruce, in his seat of Flinders south of Melbourne.

Holloway, as the leading trade unionist in the Labor Caucus, opposed the deflationary Premiers' Plan (which reduced wages and pensions), and when Scullin accepted it he resigned his position as Assistant Minister for Industry, Council for Scientific and Industrial Research, in June 1931.

With Labor's support dwindling, Holloway knew his chances of holding Flinders were slim.

He threw the support of left-wing members of caucus to John Curtin, who won the leadership ballot by just a single vote.

In 1943, when Labor won large majorities in both houses of the Parliament, Holloway became Minister for Labour and National Service.

When Curtin died in 1945 Holloway again opposed Forde's leadership bid, helping to ensure that Ben Chifley, like himself an ex-trade unionist, was elected leader.