Political parties are at one another's throats as the Rena oil-spill disaster unfolds just weeks out from the general election.

The Greens have been gaining profile as National battles the perception the Government was too slow to respond, and Labour is rewriting policy on the hoof.

One party strategist believes it will alter the tone of the election campaign and cause National to rethink.

The Greens have drawn links between the Tauranga shipping disaster and potential drilling disasters if the Government persists with its expansion of deep-sea oil exploration.


And Labour leader Phil Goff yesterday called for a halt to deep-sea drilling approvals in the wake of the Rena disaster.

"There shouldn't be deep-sea drilling until we know there are safeguards in place that can absolutely be relied upon," he said.

Prime Minister John Key accused the Greens of engaging in "political ploys".

He and Mr Goff exchanged verbal blows yesterday over pictures of the Opposition leader joining the beach clean-up, turning the tables on Labour, which continually accuses Mr Key of taking up photo opportunities.

But the Greens, with their inherent environmental credentials, are the party that could benefit most.

Party support has been increasing steadily all year and most polls now have the Greens between 9 and 11 per cent - compared to 6.72 per cent last election.

Co-leader Russel Norman isn't willing to predict the party will profit from the profile it is getting through the disaster.

"The short answer is I don't know. I don't really know how this is going to affect the election," he told the Herald.

"All I can tell you is how I feel ... We're supposed to be guardians of the environment and I just feel like we've let it down collectively.

"I just think that that thing about loving New Zealand and wanting to protect it, I think possibly that may become a stronger element to the campaign."

Labour strategist and campaign manager Trevor Mallard believes that if there are votes to be won and lost over the disaster, it is more likely to be from National to the Greens rather than Labour to the Greens.

That transfer had already occurred, he said, "and this is not likely to add to that trend. I think it's more likely to shake National's tree."

Mr Mallard said campaigning around disasters was a finely balanced thing and "parties seen to be over-egging or blatantly taking advantage of a situation for political purposes will be punished".

The balance on the other side was that where there were questions to be asked, if Opposition parties weren't asking them, they would be punished.

Mr Mallard believed the disaster would cause National to rethink its campaign.

"Clearly they can't be as gung-ho when they are in a defensive position in the way they are over this."

The pressure was evident on Mr Key's face on television, he said. "You could see it in John Key's face last night, the fact that there is now enormous pressure on the Government in this issue, and they won't be able to be bouncy and floaty in the way they would in a non-disaster situation."

Transport Minister Steven Joyce, who is also National's campaign manager, said Labour and the Greens were playing politics over the disaster and had no information on which to base their early criticisms.

"They were playing on people's fears and they were playing on people's concerns," he said last night.