Politicians of all persuasions are heading to Ratana Pa today to gauge and court Maori support.

It's part of the annual celebrations of the Ratana movement.

Maori politics expert Rawiri Taonui told Mike Hosking it remains an important event in the political calendar.

"going to Ratana is like a litmus test for measuring different degrees or Maori support."

He said Maori voters tend to change their party vote, based on who they believe has their interests in mind.

"The vote is still searching for a place that might deliver and I think that may be why Jacinda Ardern's trek to Ratana this year's going to be really important."

LISTEN ABOVE AS RAWIRI TAONUI SPEAKS WITH MIKE HOSKING