National Party MP Chris Bishop is backing leader Judith Collins after a poll put the party on 21 percent.
The poll, commissioned by right wing group the Taxpayers Union and conducted by research group Curia, put the National Party only six points ahead of ACT, which got 14.9 percent.
Labour got 45.8 percent and the Green Party 9.6.
Bishop told Morning Report 21 percent is not as high as the party would like it to be.
"Well we've got to do better, there's no doubt about it. You know, we've got a long way to go to the election, that's the good news."
He said Collins was the right person to take the party through to the election.
"She took over in very tough circumstances and, you know, she's doing a great job. And [I'm] looking forward to serving in her Cabinet."
Speaking about Collins recent comments where she called microbiologist Siouxsie Wiles a "big fat hypocrite", Bishop said he would not have used the same word but he thought his leader had a point.
MIQ bookings reopen
Bishop, who holds the profile of Covid-19 response spokesperson for the National Party said proposed changes to the MIQ bookings system to make it fairer are a band aid over a "festering gap".
Bookings will reopen on Monday after a pause due to the current Covid-19 outbreak. Once they are open there will be a virtual lobby system instead of the previous system that required constant refreshing.
Bishop said it would never be fair as long as there was no system for prioritising who gets an MIQ spot.
"It's National Party policy that there should be some sort of priority or point system, a bit like the immigration system, where essentially the more urgent the travel, the higher the points, and the more likely you are to get a slot."