'Probably time' to change my phone number - Jacinda Ardern

Jacinda Ardern says she might change her phone number in the wake of claims she received a text from a friend of Karel Sroubek.

National has been demanding the release of a text message sent by martial artist-turned-activist Richie Hardcore, who counts the Prime Minister and the jailed drug smuggler amongst his friends.

Ms Ardern has refused to reveal what it said, insists she didn't respond to it, and has called the Opposition's demands "a bit desperate".

She told Newstalk ZB on Friday it might be time to change her phone number.

"I've had the same number for 10 years so I think it's probably time I did something about that," she told broadcaster Kate Hawkesby.

She went on to explain why she's refusing to make its contents public.

"People do [text] me all the time and people email me all the time and I just, I worry a little bit about precedent there, because people, members of the public email me thinking obviously that they will be doing that with some level of privacy there.

"So I just want to work through that properly... I've given a summary of essentially what it said and it's fairly innocuous in that regard - but it's more the precedent that I'm worried about."

Ms Ardern said there was "absolutely not" a chance the text would come back to bite her "in the bum", in Ms Hawkesby's words.

"As I have said throughout… this case I knew nothing of until it was in the public domain, and obviously  that means I knew nothing of it during the decision-making process. So it is what it is."

Mr Bridges has suggested Ms Ardern may have known Sroubek before he was arrested, and that influenced the original decision not to deport him back to Europe at the end of his sentence.

The text was sent after media coverage of Immigration Minister Iain-Lees Galloway's original decision, which has since been reversed.