Judith Collins touts strong interest in soon-to-be vacated seats amid recent controversies

National leader Judith Collins says her team is "very enthusiastic" despite its low polling this week, and that there's a lot of interest following a swathe of resignations - and boots - from the political party.

Spots are open to replace Hamish Walker in Southland, Nikki Kaye in Auckland Central and Andrew Falloon in Rangitata.

Ms Collins said candidates for the seats will be announced "very soon".

"I think they'll be out in about 10 days or so. Some of them may be even earlier.

"They had a lot of candidates, or prospective candidates, to go through - a lot of interest - so I'm very excited about those."

As a warning following the turmoil within the Opposition party, Ms Collins said, "people just have to behave themselves".

However, she still had confidence in her team despite poor polling recently.

Newshub's Reid Research poll on Sunday night had Labour on 60.9 per cent , up 4.4 points. Meanwhile,  National dropped 5.5 points  to 25.1 per cent.

The Greens were on 5.7 percent, ACT on 3.3 per cent and New Zealand First on two per cent.

However, National's internal polls had the party slightly higher on 36 per cent compared to Labour on 50 per cent, with the average being 54 to 31 in Labour's favour.

"It's improving and that's the main point," Ms Collins told TVNZ1's Breakfast today. "Also, some of the polling was much closer to the 40s.

"Some of them are quite high and it just depends on the sample sizes, but I know that the Reid Research poll is one that we can discount.

"I just thought our caucus should be very aware of how well we're doing compared to where we actually had got to and they are very enthusiastic, just like me."

When asked by Breakfast host John Campbell what the party's highest internal poll result was, Ms Collins was coy.

"No, I'm not going to go down that track, John. You're so tricky," she told Campbell.