Acting Prime Minister and Labour Party deputy leader Kelvin Davis says ending oil and gas exploration is the "right thing to do".

Prime Minister Jacinda Ardern during the election campaign said she would not be cancelling any future permits.

However, the government announced last Thursday that it will not grant new deep-sea oil and gas exploration permits.

Mr Davis told Morning Report the change in direction was "a brave and bold decision".

"It's the right thing to do," he said.

"Paula Bennett was in New York signing off the Paris Agreement two years which committed us to this line and they did nothing.

"We're stepping up."

Mr Davis admitted he had not looked at Treasury advice that warned no new offshore oil drilling would cost the economy NZ$6.2 billion but said the transition would be managed over a 30-year period.

He dismissed opposition claims of job losses as "scaremongering".

When asked if cancelling future permits would cut greenhouse gas emissions, Mr Davis said "if we're not mining them, then we're not burning them".

Watch Kelvin Davis on Morning Report:

In the latest political poll, Labour has taken a hit.

The One News Colmar Brunton poll has Labour down five points to 43 percent, one point below National on 44 percent.

Ms Ardern remains the preferred Prime Minister by a significant margin, currently on 37 percent, with Simon Bridges on 10 percent in his first poll since taking the National Party leadership.

Mr Davis said if the prime minister was not fazed by the poll results, then he wasn't either. The acting prime minister says the latest political poll is an embarrassing debut for National's new leader Simon Bridges.

"When there's a change of leadership in a party, normally there's a 3 percent bounce and National hasn't had that bounce at all.

"David Cunliffe, when he became the leader of the Labour Party, entered on 12 percent.

"Simon Bridges' ego would have wanted to be up where Jacinda Ardern debuted, around about 26 percent and that hasn't happened for him."