New Zealand Prime Minister Jacinda Ardern was caught on a hot mic Tuesday using a vulgarity against a rival politician in a rare misstep for a leader known for her skill at debating and calm, measured responses.

After five years as prime minister, Ardern faces a tough election campaign in 2023. Her liberal Labour Party won reelection two years ago in a landslide of historic proportions, but recent polls have put her party behind its conservative rivals.

The comment came after lawmaker David Seymour, who leads the libertarian ACT party, peppered Ardern with questions about her government’s record for around seven minutes during Parliament’s Question Time, which allows for spirited debate between rival parties.

As an aside to her deputy Grant Robertson, Ardern said what sounded like, “He’s such an arrogant pr———,” after sitting down. Her words are barely audible on Parliament TV but are just picked up in the background by her desk microphone as House Speaker Adrian Rurawhe talks.

Ardern’s office said she apologized to Seymour for the comment. When asked by The Associated Press to clarify, Ardern’s office did not dispute the comment. In an interview with the AP, Seymour said she had used those words.

“I’m absolutely shocked and astonished at her use of language,” Seymour said. “It’s very out of character for Jacinda, and I’ve personally known her for 11 years.”

He said it was also ironic because his question to the prime minister had been about whether she had ever admitted a mistake as leader and then fixed it. “And she couldn’t give a single example of when she’s admitted she’s wrong and apologized,” Seymour said.

Seymour said that in her text, Ardern wrote that she “apologized, she shouldn’t have made the comments, and that, as her mom said, if you don’t have anything nice to say, don’t say it.”

Seymour, who said he admired some of Ardern’s political skills immensely, said he’d written back to Ardern thanking her for the apology and wishing her a very Merry Christmas.