Newly elected state upper house MP Mark Buttigieg says the decline in the number of workers joining trade unions has made the movement more relevant than ever.
The former Electrical Trades Union organiser is a long-time resident of Sutherland Shire and St George, was a shire councillor and stood for the federal seat of Cook at two elections.
He unsuccessfully sought Labor Party preselection for Barton in 2016.
In his inaugural speech in the Legislative Council, Mr Buttigieg said the union movement and its values were "the bedrock of the Australian Labor Party".
Those values were social progress, solidarity, collectivism and cooperation.
"The union movement represents some 600,000 working people in NSW and nationally some 1.6 million people throughout Australia, or about 15 per cent of all employees," he said.
"It is one of the largest single representative interest groups in Australian society.
"Much has been made in recent years of the relevance and role of the union movement in the ALP.
"The point has been made in relation to falling union membership.
"My response to this is that falling membership has made unions even more relevant than they have ever been.
"With fewer people being represented by unions, the cause for empowering working people has become greater, not less, and should strengthen our resolve to encourage union membership.
"The strength and differentiation of the Labor Party from its conservative opponents lies in its ability to create a mass movement around issues that affect many working and disadvantaged people.
"The representatives of this mass movement must comprise union members and ALP branch members and policy formulation works best when structured from the ground up, by listening to the people in our movement who are grounded in reality.
"Working people will tell us when wages are not keeping up with cost of living pressures, when electricity prices are too high, when there is bullying in the workplace, when people are being unfairly sacked and when labour hire is being used to undermine wages and conditions - not to mention how we keep employees healthy and happy and businesses productive so that the economy works for everyone and not just a select few.
"The more influence unions have and the more we listen to them, the better policy formulation we will get."
Mr Buttigieg was upbeat about Labor's election loses at state and federal levels, saying, "Losing elections by being honest does not imply the policies are wrong."
"What it does imply is that we are not bringing people along with us when we prosecute a change for the better," he said.
"Progress is always more difficult to explain than the status quo but that is no reason to abandon progress."