Jacinda Ardern has poured cold water on suggestions she try and roll leader Andrew Little.

"Never - he's doing a great job," the deputy told The AM Show on Friday morning.

"He's working really hard. I predict we are going to see a shift."

Labour needs a Jeremy Corbyn-sized shift desperately if it's to form the next Government. It's hit a new low of 26.4 percent in the latest Newshub-Reid Research poll.