EXCLUSIVE: WORKERS on all new government-funded projects including the East West Link tunnel will face mandatory drug and alcohol testing on site from the middle of the year.

The crackdown on the unionised workforce has been prompted by widespread concerns about drug use and dealing on construction sites.

Companies bidding for government work would also have to promise to include other "security measures" on site, including CCTV and biometric scanners, in a move Premier Denis Napthine said would address fraud and theft.

Dr Napthine told the Herald Sun the changes were about boosting safety and tackling "dangerous work practice".

"Reports of illicit drug use and distribution on Victorian construction sites are widespread," he said.

"The presence of intoxicated and drug-affected workers on building sites presents a real and serious risk to the safety of hard-working Victorians."

Calls for stricter measures on construction sites have grown since revelations bikies and other members of organised crime gangs had infiltrated the industry.

Last year, Victoria Police Chief Commissioner Ken Lay said there was "intelligence which indicates that people who are related to bikies or OMGs (outlaw motorcycle gangs) are selling drugs on some building sites".

The move to introduce new workplace rules has been welcomed by the Master Builders Association, which the Sunday Herald Sun revealed in 2011 wanted mandatory testing.

Dr Napthine said for companies to be eligible to tender for Victorian Government construction contracts, they must have "comprehensive drug and alcohol screening measures".

"The Coalition Government takes workplace safety seriously, which is why we are moving to complement the already good work of the Victorian WorkCover Authority," he said.

Some drug testing is done on civil construction sites at the moment, in co-operation with unions.

But the changes are likely to cause some concerns within parts of the labour movement.

"Fraud and theft on Victorian Government construction sites has a direct impact on construction costs, which are ultimately borne by the taxpayer," Dr Napthine said.

Industrial Relations Minister Robert Clark will lead a ministerial team that will prepare amendments to construction guidelines.

james.campbell@news.com.au