Unions fight back on early election

Unions have seized on Malcolm Turnbull's threat of a double-dissolution election to boost its "secret army" of campaign volunteers.

The Australian newspaper in August last year published a front-page headline, "Secret ACTU army moves on PM".

The report suggested a $30 million union campaign would target 30 marginal seats - the biggest of its kind since the anti-Work Choices fight in 2007, which helped unseat the Howard government.

The headline is now being used by ACTU secretary Dave Oliver following the prime minister's call for the Senate to pass industrial laws or face a double-dissolution election on July 2.

"We want you - join the secret army," reads an online message featuring Mr Oliver on Monday.

The message links to a unions website urging volunteers to "join the fight for our living standards".

Mr Oliver said the prime minister was engaged in a politically motivated attack on unions and workers' rights.

"This smacks of arrogance," he said in a statement.

"Instead of laying out a good plan for health and education for the parliament to consider, Mr Turnbull is holding a gun to the head of parliamentarians, demanding support for bad legislation."