Labor asked to pull advertisements from air that feature Chief Minister Andrew Barr in his office

Mr Duncan said the advertisements breached guidelines which ban the use of Assembly facilities for electioneering. The television advertisements feature Mr Barr in his office speaking direct to camera about roads, buses and light rail, interspersed with shots of transport infrastructure.

Mr Duncan wrote to Labor secretary Matthew Byrne asking him to stop using material filmed in Mr Barr's office, a request that looks likely to force Labor to scrap and re-shoot the commercial.

But Mr Byrne has interpreted the request as applying only to the Youtube airing, which he pulled down last night while the ad continued to air on commercial television networks on Wednesday night as it has since Sunday.

"The advice that we've been given says it's about the ads on Youtube so until I hear otherwise I'll make decisions based on advice from the clerk and the speaker," he said.

He would not disclose how much the ad had cost, but confirmed other filming had been done in Mr Barr's office.

"We've filmed a number of options but how we use them is yet to be determined," he said. "All our advertising will adhere to the guidelines."

A government spokesman said no decision had been made on the ad, but there would be no further filming in the Assembly precinct. It was a long-standing practice for leaders to film messages in their offices, he said, suggesting Liberal Leader Jeremy Hanson had used his office to film a criticism of the ACT budget just a few months ago.

Under the caretaker conventions government premises could be used as the backdrop for political advertising, he said, accusing the Liberals of "petty point scoring".

Liberal campaign director Daniel Clode said if the advertising was not pulled immediately it would be a "flagrant breach" of the rules and a contempt of parliament.

"I've been conscious of those rules, so I'm surprised that such an amateur mistake could be made by the government of the day," he said.

Also on Wednesday, the Liberals promised to establish the position of chief engineer if they win government, to improve the government's ability to develop and manage contracts. The party would also establish an engineers' panel to consult on major works and an infrastructure plan to guide residential areas, transport connections and areas for denser housing and employment.

The Greens said they would work to phase out gas.

They would seek to ban new gas hot water systems in homes, stop the rollout of gas infrastructure to new suburbs and remove incentives to install gas. They want a rebate to help householders replace gas appliances with electrical appliances.

The Greens say gas is the third largest contributor of greenhouse gas emissions after electricity and fuel. The Liberals have rubbished the Greens' plan, saying Canberrans were sick of being lectured to, the plan was unfair, would hurt families who relied on gas, and showed the Greens were out of touch.

But the Conservation Council executive director Larry O'Loughlin said it was necessary if Canberra is to achieve zero net emissions. He said the Liberals' position potentially locked them into providing expensive gas infrastructure into the future.

Labor has also promised to appoint a preventative health coordinator to focus on strategies to reduce smoking, alcohol, obesity, diabetes, heart disease and depression.

The announcement follows a series of other health-related policies over the past week, including the major upgrade of Canberra Hospital, a nursing training package, and free meningococcal B vaccines for babies.