He ultimately decided "I didn't want to, slept on it, and called Judith Collins this morning to say I wanted to finish in Wellington and get back to family and other interests in Auckland".
"Judith was very gracious. She's as tough as I knew she was but I didn't realise she is also kind and also very funny until she took over a couple of weeks ago. I thanked her and Gerry Brownlee for the opportunity and support they had given me, especially after Todd Muller's demise, and said I think they now have a terrific team who has a good chance of winning the election, or at least can ensure the National Party will remain a broad church after 19 September."
Hooton wrote in the post that the time was right for him now to move on.
"I can't justify the impact on my family and other personal and professional responsibilities for another seven weeks. I'm pleased to have contributed to getting some of National's basic messaging done, including the standard stump speech, and also to have helped kickstart the A-to-Z policy process again."
This afternoon Megan Campbell, National's chief of staff, told MPs and staff that "today is Matthew's last day with us", a short time after being contacted by the Herald.
"Judith and I would like to thank Matthew for staying on during the transition and providing excellent strategic advice. He is now returning to his other personal and commercial interests in Auckland. We wish him well in the future."
Campbell also announced former Dominion Post reporter Michael Forbes was being promoted to deputy chief press secretary.
A director of policy will be appointed and will be starting early next week, Campbell said.
A former National Party staffer, Hooton developed into an influential columnist in the NBR before leaving in acrimonious circumstances after former Cabinet Minister Steven Joyce sued the publication over one of Hooton's columns.
Hooton apologised to Joyce and resolved the dispute, but NBR publisher Todd Scott continues to battle with Joyce in court to this day.
Hooton then moved to the New Zealand Herald as a columnist.
In the lead-up to Muller's successful challenge to former leader Simon Bridges, Hooton wrote positively of Muller and would eventually declare that National MPs had no choice but to elect the Bay of Plenty MP as leader.
Hooton was in Parliament to watch Muller's first speech as leader and it emerged he was part of a small team helping Muller's challenge.
It was announced later that he would continue on a short term basis, expected to last until the election.
Hooton continued when Collins became leader after Muller's abrupt resignation after less than two months as leader.
He and Collins agreed this morning that his work should come to an end.
