The Labour Party is celebrating an explosive boost in support - and it's all down to the "Ardern Effect".

In the latest Newshub-Reid Research poll Labour has jumped 9 points up to 33.1 percent.

This is the party's highest percentage in our polling since January 2014 when it was 33.5 percent.

But it doesn't appear to have had much effect on National's numbers - they're down 0.8 to 44.4 percent.

Significantly though, this is National's lowest percentage in more than 10 years. It was only lower in March 2007 when they achieved 42 percent, just after John Key took over as leader.

The poll was conducted from August 2-8; the first day of polling was Jacinda Ardern's first official day in the Labour leadership job.