There's more bad news for National with new polling data showing public support continues to fall.

The AM Show host Duncan Garner says he was given access to the Government's internal polling data this week, which shows Labour at 46 percent and National at 37 percent.

This is a fall of six percent compared to the last 1NEWS Colmar Brunton poll, released two weeks ago, which showed National on 43 percent and Labour on 45 percent.

Appearing on the show on Friday, National MP Judith Collins says there have been ongoing difficulties for National.

"If you stretch it out it's obviously been going along for a little while, and we've also had leaks going on this year and now strangely enough the leaks have absolutely stopped," she told Garner.

"I know we've gone through some pretty difficult times in the last few weeks or months and I'm sure we're very focused on doing our job. Which is better than Iain Lees-Galloway."

If accurate, it's bad news for National leader Simon Bridges, who has said he would bring his party back ahead of Labour within weeks.

"We'll be back ahead of Labour very soon, I have no doubt about that," he told The AM Show at the end of October.

He backed this up in other interviews, telling RNZ's Morning Report "you give it a few weeks, someone will do another poll and you'll see the National Party ahead of Labour" and Newstalk ZB that "43 [percent] is temporary and we'll quickly surpass Labour again in these polls".

When pressed on whether he would stand aside if National's polling continues to drop, Mr Bridges said, "I'm not going to get into those things, because under my leadership, that's never going to happen".

"I know over recent months we have strengthened and strengthened because of the weakness of this Government, and the unity and strength of my party," he told The AM Show in October.

"We will get stronger, and I think you'll see that in the next polls."

Newshub.