Labour MP for Ikaroa Rawhiti Meka Whaitiri was in a select committee meeting when the news broke.
"The first time we got an inkling of the Prime Minister's resignation was when the National MPs got called to an urgent teleconference," she said.
When the remaining MPs were informed, Whaitiri said it had been "a bit of a surprise".
"We never had any inkling about it, but we still respect that at the end of the day it's the Prime Minister's decision," she said, adding it was quite unusual for a PM to resign outside their term.
In terms of the effect this could have in Hawke's Bay, the Labour MP said once the initial shock of Key's resignation subsided, "we are still going to carry on, the sun's going to come up tomorrow and we're still going to have our multiple challenges in the Hawke's Bay".