Sir John Key says Simon Bridges is 'doing well' - but won't talk about Labour

Sir John Key says National Party Leader Simon Bridges is "doing really well" and has shied away from criticising the government at today's National Party conference.

Mr Key, a former Prime Minister of three terms, was asked what he thinks of Mr Bridges' leadership.

"I think he's doing really well," Mr Key said.

"His message today was the right message - and that was that politics is always about individuals.

"I mean, it's a very personal decision, voting, and the people want to know that the govenrment they elect is going to change their lives.

"He's doing really well there."

Mr Key said the 55-member National Party caucus is "the biggest and probably strongest" the party had seen.

He also said that being the opposition leader came with significant challenges which could make it difficult for individuals to shine.

"Opposition is a difficult place, so you're always going to get criticised," Mr Key said.

"We were a government that I think achieved a lot over that nine-year period, and it is tough being in opposition and it is so much easier when you are in government.

"I hate to say it, but you have lots of ready-made opportunities and chances, really, to shine, and it's harder ... for those in opposition.

"I think he's doing well, personally."

Responding to Judith Collins rising on the preferred Prime Minister polls, My Key said he "wouldn't read too much into that," but also described Ms Collins as "a very effective member of caucus."

"I think there's a strong message here [the conference] of unity in the party and in the caucus, from what I can see, and that's important as well," Mr Key said.

"It's sort of an inevitable part of politics, but I don't think he's terribly worried.

"What he's far more focused on is making sure he connects with New Zealanders, because they're the ones who ultimately make you the Prime Minister."

Mr Key would not be drawn on what he thought of the current Labour government so far, nor would he comment on the state of the economy.

"It's really for me to critique them," he said.

"People know by the sheer fact that I was the leader of the National Party for a decade and I'm here at the National Party conference where my allegiances are.

"I wish any government well because you know, I'm a passionate New Zealander, but in the end obviously I'm always going to want to see a National government."