Energy and Resources Minister and Tauranga MP Simon Bridges is today praising Labour leader David Cunliffe's u-turn over the possibility of oil exploration in the Maui's dolphin habitat.

After condemning the exploration licences issued by the government to open up 3000 square metres of the marine mammal sanctuary on the North Island's west coast, David Cunliffe changed tack.

Rotorua candidate Tamati Coffey led a march through Tauranga on Saturday.

He told 3 News last night that after looking into detail the possibility of oil exploration in the Maui's dolphin habitat is possible under a Labour government, as long as there is no threat to the species.

'We're not saying existing operations should be curtailed because there is no evidence we are aware of harm to Maui's dolphin. There could be [exploration] as long as there is no harm to the Maui's dolphin,” he told 3 News.

Simon today says he is pleased the opposition leader has taken time to look into the issue.

'I'm glad that the Labour leader investigated the evidence and that was important because the government has been very careful about being evidence based on this,” says Simon today.

'We would never jeopardise the Maui's dolphin, in fact have done a lot to safeguard them. I was very disappointed by the scare mongering by local Labour candidates and in particular Tamati Coffey on this issue.

'But it's good that the leader, rather than listening to new candidates, has taken stock of the evidence and come to a responsible position.”

Rotorua electorate candidate Tamati Coffey organised a protest march in Tauranga on Saturday proclaiming the government decision to release exploration licences in the New Caledonia Basin is further endangering the Maui's dolphin, of which only 55 are left.

'The best evidence in the government reports makes clear that nearly all of the harm is from fisheries,” says Simon.

'That's why we have done a lot on increasing the set net ban in the relevant areas where the Maui's dolphins had been sighted. The risk from petroleum activity is incredibly small.”

He says there's a mandatory code of conduct for seismic surveying in the New Zealand exclusive economic zone that is probably the best in the world.

Every single vessel has on board an independent marine mammal expert, who has the power to suspend operations on any kind of identification of marine mammal life, says Simon.

'There has not been a single Maui's dolphin sighting over many years where current petroleum activity is,” says Simon.

'It's lunacy to shut down a $3 billion a year over 7000 people industry without any good evidence. The Pohokura gas field, part of which is within the marine mammal sanctuary, provides 40 percent of New Zealand gas, heating homes, lighting stoves. From that one gas field the government receives $200 million a year in royalties.

'If you haven't received a single sighting or a single incident involving Maui dolphins in that area, why would you shut it down?”

Speaking with SunLive today, Tamati remains firmly opposed to drilling around the dolphin sanctuary.

'Our stance going forward is we are looking for better outcomes for the Maui dolphins, that means no new permits,” says Tamati.

He says the dispute is about an overlap, where the offshore oil exploration licence area encroaches on the coastal sanctuary.

'There's an overlay. That's what we are contesting. When we were marching the other day, that's what we were talking about - that overlap area.

'Whether it's oil and gas exploration, or the set nets that are doing the damage, our call was actually to do more than we are currently doing to help protect these dolphins.

'Something needs to be done. In 2004 there were 100 plus, now 10 years later there are only 55 of them left. The population is declining.”

In the last two years, the Scientific Committee of the International Whaling Commission (IWC) issued urgent recommendations about the need to protect the dolphins' from fishing nets, saying the dolphins could be extinct by 2031. New Zealand has failed to implement this advice.

With less than 15 breeding females, Maui's dolphins are amongst the rarest and most endangered mammals on earth.

Fishing progressively reduced their numbers from around 1800 individuals in the 1970s to just 50. With numbers this low, the death of more than one individual every 10-23 years will have devastating consequences for the entire population.

In 2012, a Government appointed panel of experts determined that gillnets and trawling kill five Maui's dolphins each year.

Dr Liz Slooten from the University of Otago estimates that extensions to fisheries exclusion zones, introduced since then, reduce the level of Maui's dolphin bycatch to 3.28 - 4.16 individuals per year - 54 times the sustainable limit.

'Conservation Minister Nick Smith acknowledges that fishing poses the greatest threat to the Maui's dolphins”, says Thomas Tennhardt, Chief Executive of German conservation group NABU International.

'Yet New Zealand is ignoring urgent calls by every conceivable international scientific body to immediately prohibit the use of gill and trawl nets in Maui's habitat to reduce bycatch to zero.”

NABU International's Head of Endangered Species Conservations, Dr Barbara Maas says the marginal increase in fisheries protection put in place by the New Zealand government falls significantly short of the zero tolerance approach to bycatch mortality mandated by science. It will at best delay the dolphins' demise by 4-18 years.

Read more about Maui's dolphins' looming extinction here