Opposition leader Bill English says the new Labour Government is already "brutal" and has promised to do nothing to smooth the path of the new Government.

Mr English was addressing media after announcing Opposition portfolios, a minor reshuffle that's seen Judith Collins promoted to the front bench.

The comments came in response to Health Minister David Clark saying he is "very seriously considering" accepting resignations from District Health Board (DHB) heads that aren't on the new Government's "wavelength."

"I'm extremely disappointed," Mr English said.

"I thought the Jacinda Ardern Government would be different. It turns out it's just the same old Labour trying to do its brutal tactics on the public service."

Dr Clark told RNZ he may ask for resignation letters from current chairs of DHBs before choosing which ones to accept back into the fold.

"I want to be sure that the district health board chairs are in agreement with the current Government's agenda and direction," Dr Clark told RNZ.

The comments from Mr English - and his decision to promote Ms Collins - are an indication of what National could be like in Opposition.

"We have no obligation to smooth [the Government's] path," he said, later repeating it's not the Opposition's job "to make this Government run".

That could point to National doing all it can to stall progress on Labour's legislation - which is pretty much the job description for 'Opposition Party.'

As for Ms Collins, "I think we will find that her way of doing business suits Opposition," Mr English said.

Newshub.