The man, who is yet to be identified, was working for Kenoss Contractors at a construction site in Turner last Friday when his truck came into contact with overhead power lines. He was found lying by his truck after the incident and was transferred from Calvary Hospital last week to St George Hospital in Kogarah, where he died last night.

Worksafe ACT has since closed the worksite because of the incident and says it won't be reopened until it is declared safe.

Another Kenoss Contractors construction site in Molonglo has been closed since the incident because of safety breaches.

The man was in a critical but stable condition in St George Hospital's intensive care unit for most of the week. A spokeswoman from the hospital confirmed at 9pm last night the patient had died. The matter has not yet been referred to ACT Policing, a spokeswoman said last night.

But ACT Work Safety Commissioner Mark McCabe said the matter would be for the coroner and that Worksafe ACT and the Australian Federal Police would be investigating the incident.

''What we have to find out is why did this happen, was it something that could have been avoided, should someone be held accountable, should there be something that we do to make sure it doesn't happen again?'' Mr McCabe said.

One man died on a non-Kenoss construction site in Canberra in December last year. Mr McCabe said yesterday's death was the second on a Canberra civil construction site in the past six months.

The Construction, Forestry, Mining and Energy Union has called for the ACT government to prioritise safety and good employment practices when it tenders government projects.

The ACT Greens have backed union calls for the government to put safety on worksites first.

The party used question time yesterday to ask the ACT government to table information in the Assembly about the recent major construction contracts it has awarded, including whether the winning companies were ''simply the cheapest''.

Greens industrial relations spokeswoman Amanda Bresnan said, ''There are concerns the government is favouring the cheapest companies, particularly for construction projects, and that this is compromising safety and opening the door to some poor subcontracting.

''We've also questioned whether the government undertook due diligence on Kenoss, particularly as the safety issues that have arisen relate to the company's 'systems of work' rather than specific hazards.

''It's disappointing the government wasn't able to answer today if all sites in the ACT operated by Kenoss had been identified and inspected.''