National MP Simon O'Connor to marry Minister Simon Bridges' sister

Rachel Trimble and Simon O'Connor. Photo / Supplied

A change of heart meant Simon O'Connor wasn't ordained after priesthood training and now the MP for Tamaki is getting married to the sister of his colleague Simon Bridges.

Mr O'Connor, who entered Parliament in 2011, got engaged to Rachel Trimble early in the new year after dropping a knee on the top of Mt Maunganui.

"She has been encouraging me to ask the question for about a year, gentle encouragements," he said.

"I am slightly more slow and cautious, it doesn't matter if it is politics, policy or relationships."

It was the second time in the day that they had been up the mountain. Other plans meant there was too much of a rush the first time, so Mr O'Connor insisted on another walk up later that day.

"You don't really want to pop a question and go, right [we're out of here]. So it worked out perfectly well, the sun is going down, walk completed, and surprised her completely. So much so I had to ask again."

Ms Trimble is a trained engineer and a maths and science teacher at Mt Hobson Middle School.

The pair met shortly after Mr O'Connor ran for Tamaki, when Ms Trimble held a meet-the-candidate morning tea.

"We hit it off ... a couple of weeks later I invited her out for a coffee to follow up some of the discussions we'd had, and it built from there."

Mr O'Connor already knew Mr Bridges through the National Party. His future brother-in-law and other family will attend the Auckland wedding in December.

The Tamaki MP will then move into his new wife's home, where she lives with three of her five children.

Mr O'Connor is about to turn 40, and his fiancee has just turned 50: "We will be celebrating, a bit tongue in cheek, a joint 90th birthday in a few weeks."

After leaving university Mr O'Connor completed nine years of training to become a Catholic priest, but decided not to seek ordination.

"When I chose to leave 10 or so years ago, it wasn't to get married per se, but it became an option, and now it has become a reality."

Media attention has meant news of the engagement has spread.

In Parliament, Labour's deputy leader Annette King said Mr O'Connor had not shared his good news at a recent committee meeting, and that could have been an attempt to get out of shouting morning tea.

"Can I suggest next week that Mr O'Connor will be shouting us a very luxurious, healthy morning tea at the health select committee. But congratulations, and I always love a happy ending."