Greens say Abbott shamed over commission

Former prime minister Tony Abbott should hang his head in shame over the trade union royal commission after it effectively cleared Opposition Leader Bill Shorten, Greens leader Richard Di Natale says.

The commission released a statement late on Friday indicating the inquiry's lawyers had made no submission that the federal opposition leader engaged in any criminal or unlawful conduct during his time at the helm of the Victorian Australian Workers' Union.

Senator Di Natale said the submissions revealed the investigation for what it was, a "stitch-up" and an attempt to tarnish the Labor Party.

"To embark on an expensive royal commission in an attempt to get an opposition leader is a shameful abuse of process and Tony Abbott should hang his head in shame for doing it," the senator told reporters in Adelaide on Saturday.