The Fair Work Ombudsman has launched an investigation into John Setka’s threats against the AFL after Workplace Relations Minister Tony Burke flagged the Victorian union leader’s planned actions could be unlawful.

The investigation comes as South Australian Premier Peter Malinauskas warned the CFMEU’s industrial campaign against the AFL was not in the interests of the broader labour movement, while the opposition attacked Prime Minister Anthony Albanese for sticking by his line that Mr Setka’s threats were “a matter for the AFL”.