It is understood the funds public donations controlled by ALP campaign managers have been withheld in response to radio and TV advertisements that appeared to ally him with the green vote.

Mr Hettinger, who publicly calls himself ''green Labor'' and narrowly missed out on election in 2004, is an outspoken activist on education and environmental issues, memorably arguing publicly against his own party during Save The Ridge campaign against the Gungahlin Drive Extension.

The ads come after a Patterson-Canberra Times poll showed the green vote was likely to decide the election. The television ads use a large green banner to promote Mr Hettinger's slogan and show the candidate saying he was for ''a smarter and greener Canberra''.

The ALP logo is partly obscured on the screen.

Labor's move, which took place late last week, took Mr Hettinger by surprise.

''I found out about the frozen funds by a phone call from headquarters just before the weekend but haven't heard anything since,'' he said. ''It is hard to speculate why they have done it, but I will not back away from my ads. There is nothing controversial in them.'' He remained outspoken yesterday and said he was no ''Johnny-come-lately'' to a green-inspired campaign.

''I have always had green principles,'' he said. ''And I have not been afraid to stand up for them. I was arguing for these sorts of principles before they became popular. I was way ahead of the game in 2004.''

Mr Hettinger denied he was considering a split with the Labor Party but agreed he thought the removal of funds was a drastic tactic.

''What I found so odd is that something so minor like an ad could have such a reaction. But you can see what happens in different branches of the ALP when someone is seen to be out of line. Yet, then again, everyone seems to stay in the party.''

Labor's ACT secretary, Matthew Cossey, would not comment on what he said were internal ALP matters but confirmed that candidates were required to stay within certain bounds. ''We also have a candidates' code of conduct each person must sign ... It is a legally binding contract.''

He would not say if Mr Hettinger had breached the code of conduct.