The Red Flag has flown over Trades Hall since 1918 as a symbol of solidarity with the International Labour Movement. Its first appearance, at a Trades Hall Council meeting in 1918, was "greeted with hearty acclamation". Almost immediately, however, the Federal Government issued a prohibition against flying the flag.

Writing to Trades Hall on the issue, acting Prime Minister William Watt appealed to nationalistic sentiment, arguing

That decision at this crucial war period is a direct challenge to the patriotic sentiments of a large majority of Australian citizens… I feel that the relatives and friends of those who are fighting for the liberty and safety of our country and race should be spared this indignity.

Trades Hall President E.F Russell’s reply was swift:

I do not consider the red flag to be a menace to anyone but tyrants who are fattening and battening on the workers of every country – profiteers. (The flag) expresses the hope that the workers of the world one day will be united to prevent all wars and bring universal peace and brotherhood to all mankind.

The decision to fly the flag in direct defiance of the Federal Government was not taken lightly; the Lift Attendants Union left the Hall in protest over the controversy.

Despite decades of controversy the Red Flag, along with the Eureka and Aboriginal flags, still flies over Trades Hall to this day, a constant reminder of the international solidarity that is essential to the future of workers movements around the world. We demonstrate this solidarity through support for international workers’ campaigns such as the struggle against apartheid.