The Victorian building watchdog will crack down on union delegates' entries to work sites.

It is a practice that some authorities say takes a big chunk out of potential productivity, but unions say they need delegates onsite to ensure safety is maintained.

The Victorian Construction Code Compliance Unit says it has been working more closely with the Victorian WorkCover Authority and Victoria Police to enforce right-of-entry laws.

A number of CFMEU officials have been arrested for allegedly trespassing on construction sites, including Mick Powell and Peter Clark, who police say entered the Ringwood Aquatic Centre redevelopment site in Victoria without authorisation.

Reports say the organisers had entered the site on warnings of health and safety breaches. The two officials are now faced with trespassing charges.

A spokesperson for Victorian Attorney-General Robert Clark says there will be a full review of the ways that laws are enforced.

“The CCCU, Victoria Police and the Victorian WorkCover Authority are working together to ensure Victorian and Commonwealth laws are used as effectively as possible to promote safe, law-abiding and productive building industry workplaces in Victoria,” spokesman James Copsey told the Herald Sun.

““Building workers have a right to be safe at work,” a Construction Forestry Mining and Energy Union (CFMEU) spokesperson said.

“The CFMEU is seeking its own legal advice on those issues.”

Master Builders Victoria says it is fairly common practice for union officials to enter a site under the guise of workplace safety when they are really there for some other purpose, and that actual workplace safety is paramount above all politics.

There has been some speculation that changes to industrial relations laws may be on the horizon for Victoria.