Labour MPs in the Bay of Plenty are reacting to the news of Prime Minister Jacinda Ardern's resignation, announced yesterday.

Labour's caucus is set to decide on a new party leader via a vote this Sunday. Ahead of the selection, local MPs are posting their tributes to the outgoing Prime Minister.

In a post to Facebook, Tauranga based MP Jan Tinetti says "no words can convey" how she feels about "this remarkable woman".

"Not only has she been the most incredible boss but she has been a huge support to me in a personal capacity, I will never, ever forget the support and aroha she gave to me when I was diagnosed with breast cancer," says Tinetti.

"Jacinda is a great leader, the hardest working person I have ever met but above all that what will always stand out for me is that she is a kind, generous, fiercely loyal person of the utmost integrity."

Rotorua based MP Tamati Coffey made a similar post, saying he and the Labour Party "stand with her today".

"Jacinda announced today that she is leaving politics and will not go further as the PM of Aotearoa NZ," says Coffey.

"She has led us through the COVID pandemic, the Christchurch shootings as well as many natural disasters and she has done it with kindness and empathy for the last 5 years."

Angie Warren-Clark, another Labour MP based in the Bay of Plenty, also has posted a tribute.

"People always ask me what Jacinda is like in person. So on this day when my friend and our Prime Minister has announced she is stepping down - here's the intel," says Warren-Clark.

"She is tremendously kind, funny, empathetic and most importantly authentic. What you see on TV is exactly what you get with her. Jacinda runs our Country, does a stand-up interview and then asks after my husband and our cats.

"She's a legend whether leading us through a crisis or chatting about girl-stuff and world politics. Her sharp intellect, her emotional IQ, her grace under attack and her fierce loyalty and dedication to our nation have made me feel so proud of her, so lucky to be a part of her team and so grateful to have had this amazing woman leading us through the good times and the dark.

"I cried today for my boss, for her courage and integrity and for doing the right thing for Jacinda and her family. The mark of a true leader is to lead with everything and then when the tank is empty walk away knowing you've left this place better.

"It takes true leadership to be honest about not having enough gas in the tank for the next fight. That confirms for me even more that Jacinda was here for the right reasons. For our Country. For us all."

SunLive approached Bay of Plenty based National MPs Todd Muller, Sam Uffindell and Todd McClay for comment.

Ardern is set to step down by Tuesday, February 7. She says she will remain an electorate MP until the end of April to spare the country a by-election.