Retaliation fears if construction union leaders return

Work needs to be done to weed out corruption in the construction industry, a report says. (Jono Searle/AAP PHOTOS)

Legal challenges from ousted officials have delayed reforms to a major union placed under administration following damaging reports of corruption and criminal influence.

Mark Irving has delivered his first report to the government since being appointed administrator of the construction division of the CFMEU in August, which was tabled in parliament on Tuesday.