Jacinda Ardern has spoken to Napier MP Stuart Nash, after he swore at an Air New Zealand staff member.
The Prime Minister told Hawke's Bay Today she had spoken to Nash on Thursday.
"I spoke to Minister Nash yesterday to reiterate my expectation that he will conduct himself professionally and politely at all times."
"I understand he apologised on the day, but it's my expectation this won't happen again."
Nash was attempting to take a flight from Napier to Wellington on July 3, arriving at the gate 25 minutes before the flight departed.
Two days prior Air NZ had changed its policy meaning passengers travelling without luggage had to check-in first.
As such, he was denied access to the flight.
Nash said he had said "words to the tune of 'for bleep sake'," with bleep, in this case, indicating a four-letter swear word.
"I was a little bit grumpy," he said.
But he said, "you should never shoot the messenger".
"I'm the first to admit I, perhaps, acted in a way which I shouldn't have.
He later apologised for the incident.
It is not the first time Nash has made headlines for losing his temper.
Earlier this year security had to stop a confrontation between him and another gym goer at the parliamentary gym.
At the time Speaker of the House Trevor Mallard said he was told that both men were being "loud and uncouth", and that Nash had apologised to the man the following day for his "bad language".
However, it was not serious enough for security to report it to Mallard, who said he found out because Nash told him.