Simon Bridges says the Government clearly isn't delivering on its promises, or else it would be "much higher in the polls".

The National Party leader is fending off rumours he's about to be rolled. Duncan Garner, host of The AM Show, told Bridges on Monday morning he's been told by members of the National Party caucus they're not happy with how Bridges is performing.

Recent preferred Prime Minister polls have him at just 5 percent, level pegging with former leadership rival Judith Collins and well behind Prime Minister Jacinda Ardern on 51 percent.

"There's a mature understanding that in the aftermath of attacks you will see a rallying around the Government," Bridges told Garner. "But what we know is we need to hold them to account. We're doing that."

He said "not a single member" of his party has expressed dissatisfaction with his polling, which after 14 months has rarely reached double-digits.

"They're not unsettled. No they're not. Not a single member has said that to me... We've got a job to do. It's not about ourselves. Discipline and unity is important."

He says it's actually Ardern that's in trouble.

"They're not delivering. Actually if they were, they'd be much higher in the polls."

Labour rated 48 percent in the latest Colmar Brunton poll, about level with National's best-ever election performance under MMP (47.3 percent in 2014). National got 40 percent.

He told Garner if he's "so obsessed" with Collins, he should ask her what her plans are.

"I'm not telling you what I will or won't do. You ask her about it."

He did less than two weeks ago. Collins told him there was more chance of Green co-leader James Shaw being rolled than Bridges.

"People need to always remember I've always been a very loyal member of the National Party caucus and the team, and I always support the leader of the National Party."