National leader Simon Bridges says he regrets using the word "embarrassing" to describe MP Jami-Lee Ross' health issues.

"I regret it, I think it was a poor choice of words," Bridges told reporters today.

"As I clarified, and I've said now a number of times, I was simply saying that anyone, whether an MP or not, would prefer personal health matters are dealt with in that way rather than public."

He reassured the people of Ross' electorate of Botany that they still had an MP.

"Jami-Lee Ross will be doing some constituent work there and keeping in regular contact with his staff."

Bridges used the term "embarrassing" a number of times during a press conference on Tuesday to discuss Ross' decision to step away from politics for a few months.

Prime Minister Jacinda Ardern said yesterday she would not have used the word.

"We all get judged individually for the way we lead our own teams. I'm responsible for the way I lead mine and I hope I do that in a way that really does look after our team's wellbeing," she said.

She wished Ross well.

On Tuesday, Ross said in a statement he was taking some time off to focus on "personal health issues".

It was a decision that surprised Bridges, who told media it "came out of the blue".

Bridges has said Ross' decision was unrelated to an investigation into who leaked details of his travel expenses to the media.

The investigation commissioned from PwC by National, is expected to report back in as little as a week.

Bridges said today he expected it would be made public.