US trade unionists headed home from Los Angeles today buoyed by a fighting AFL-CIO quadrennial congress.

Labour activists met this week faced with the heady task of revitalising a dwindling trade union movement.

Delegates voted to support a landmark resolution throwing the doors of the AFL-CIO open to every worker.

The vote was hailed by some as the biggest shake-up of the US labour movement since a section of the American Federation of Labour broke away in 1935 over refusal to organise low-skilled workers and formed the Congress of Industrial Organisations.

The resolution read: "The AFL-CIO hereby invites every worker in the United States to join the labour movement either through an affiliate or through Working America" - the AFL-CIO affiliate for non-union members.

It said workers had been "confined within bargaining units defined by government agencies or limited to workplaces where a majority of employees votes Yes in the face of a ruthless campaign by their employer to deny them representation."

Communications Workers of America president Larry Cohen told delegates that "all workers who want to take collective action to improve wages, hours and working conditions" make up the labour movement.

"It is our task to do nothing less than to create a new mass working-class movement in this country," he said.

That echoed AFL-CIO president Richard Trumka's opening address in which he said the 13-million strong union federation had to "turn America right side up."

The US trade union movement has come under increasing pressure from rightwingers eager to seize on the economic crisis to attack workers' rights and collective bargaining since the AFL-CIO's last congress in 2009.

It led the union body to declare that the country's labour law "no longer fulfils its promise to US workers."

It passed a resolution calling for new labour laws to replace the 1935 National Labour Relations Act which unions said had been subverted by legal amendments and "a multibillion-dollar industry of 'union-avoidance' consultants."

Congress called for a "vibrant" campaign to redress the inequality in the bargaining relationship.