Union boss Howes calls it quits

Australian Workers' Union national secretary Paul Howes has confirmed he will step down from his role in July, but not to run for parliament.

Mr Howes, who has been in the union role for seven years, said he would "cherish his membership ticket" forever.

"I know my decision may come as a surprise," he said in a statement.

"But I was elected to this role seven years ago, at 26 years of age. I left school at 14, and commenced full-time work in the union movement at 17."

Mr Howes said he wasn't leaving the job in order to pursue a seat in parliament.

"For some time now I have been contemplating the next steps in my life. And as such I recognise the right thing to do is to step down," he said.

He said the AWU was in better shape than ever, with a growing membership and united leadership team.

Mr Howes is expected to be replaced by assistant national secretary Scott McDine.

Opposition Leader Bill Shorten hoped Mr Howes would continue his "valuable contribution to workers' rights" in the years to come.

"Paul's passion for workers' rights and fighting for safe workplaces is well known - he is respected by industry, unions and government alike," Mr Shorten said.

Mr Howes replaced Mr Shorten as national secretary of the AWU.

ACTU secretary Dave Oliver said Mr Howes had shown an "unwavering belief in a modern, vibrant, campaigning union movement".

Mr Oliver said the AWU boss had rebuilt bridges with other unions.

"Paul has been a reforming national secretary, putting old wars in the past and driving new strategic alliances in manufacturing with the AMWU, in mining with the CFMEU and offshore with the MUA."