Whether O'Connor holds the seat will depend on whether he holds the support of the local party members and delegates. It is rare for a sitting MP to face a challenge in their own electorate. O'Connor held the seat with a 8000 majority last election.
All National candidates - including current MPs - have to go through National's new screening processes this election, including police checks and vetting of their social media and pasts. The party has further tweaked that after Tauranga MP Sam Uffindell disclosed a bullying incident at King's College, but that was not passed onto the delegates voting in the selection, party members or the public during the byelection.
O'Connor hit the headlines earlier this year for posting "today is a good day" on social media in response to the US Supreme Court overturning the Roe v Wade decision, opening the way for US states to make abortions illegal.
O'Connor took the post down at the request of leader Christopher Luxon, who is anti-abortion, but who said it was causing distress and did not represent the National Party position. Luxon has pledged not to change New Zealand's abortion laws if he is in Government.
O'Connor said his moral views were widely known by the electorate from the beginning of his political career. While they were occasionally highlighted by events such as conscience votes on issues such as euthanasia and abortion reform, he said they were usually in the background.
"They know I hold strong views but the main things we talk about are issues such as the cost of living and housing, not moral issues. [Those issues] may burn brightly for a few days, then they fall into the background where they should be," he said.
O'Connor is Simon Bridges' brother-in-law, and was one of the first to jump to Bridges' defence when former leader Collins tried to demote Bridges in November last year over an off-taste joke several years earlier. Ahead of the caucus meeting at which Collins was voted out of the leadership, O'Connor said he refused to serve under her and would surrender his portfolio areas if she remained leader.
Collins, who is expected to be re-selected as the party's Papakura candidate, lives in the Tamaki electorate.