Jacinda Ardern has fired her immigration minister after being tipped off by the opposition leader that he had engaged in a 12-month-affair with a staffer in his office. New Zealand’s prime minister said on Wednesday that Iain Lees-Galloway had accepted his situation was untenable, and Ardern was concerned that an abuse of power may have taken place. The affair took place over a 12-month period and ended several months ago, Ardern said. Ardern’s office was tipped off about the affair by Judith Collins, leader of the National party, who provided details of a third party who confirmed the affair directly. The prime minister said she was satisfied the accusation was “substantiated” and Lees-Galloway had confirmed the details himself. Ardern said she was unaware of the affair before being informed by Collins and said that she had wished Lees-Galloway had told her. He was dismissed on Tuesday but went home to share the news with his family before it became public on Wednesday. According to his parliamentary biography, Lees-Galloway is married to an early childhood teacher and they have three children. Ardern said her minister – whose portfolios included workplace relations and safety – “showed a sustained lack of judgment over a long period of time”. “The minister has shown a lack of judgment over a period of 12 months. In undertaking this relationship he has opened himself up to accusations of improperly using his office,” Ardern said. “He has not modelled the behaviour I expect as a minister that is in charge of setting a standard and culture in workplaces. His actions have led me to lose my confidence in him as a minister.” Ardern said she wanted to reform the parliamentary culture so it could regain the public’s trust. The minister’s dismissal comes one day after National party MP Andrew Falloon resigned after it was discovered he sent a nude picture message to a female university student. MP for Palmerston North since 2008, Lees-Galloway said in a brief statement he apologised to everyone he had hurt, and asked for privacy for him and his family. “I accept the prime minister’s decision and apologise absolutely,” Lees-Galloway said. “I have acted completely inappropriately in my position and cannot continue as a minister. I have apologised to my family for letting them down. Please appreciate their privacy. “I also apologise to anyone who has been hurt by my actions.”