Sacked Cabinet minister Iain Lees-Galloway has apologised to his family for the "trauma" and "humiliation" they experienced as the result of his affair with a former staffer.

"The trauma they have experienced has been excruciating," he said in his valedictory speech to Parliament this afternoon.

Lees-Galloway was sacked from Cabinet by Prime Minister Ardern two weeks ago, after he admitted to an extramarital affair with a former staffer.

His position as a minister was no longer tenable, according to Ardern, given his Workplace Relations responsibilities.

Lees-Galloway is one of five MPs giving their farewell speeches to Parliament today - the others are Labour MP Raymond Huo, the Greens' Gareth Hughes and former Labour ministers Clare Curran and Ruth Dyson.

In today's speech, Lees-Galloway admitted that the relationship with the staffer was not appropriate, and acknowledged the power imbalanced involved.

Lees-Galloway spoke of the "dehumanising trauma" that he, and his family, experienced after he said they were used for "headlines and clickbait".

"I am sorry for the hurt and humiliation I have inflicted on my family and for the direct impact my actions have had on so many others."

But he said his family were "tough cookies": "We will come out of this stronger, together".

When he looked back at his life, it would be divided into two periods – before 2020, and after 2020.

He said it has been a rough year: "There was the near-end of our marriage, the death of my father and now the end of my political career. We even had to put the dog to sleep a few weeks ago."

Praise for PM

Less-Galloway said this term of Government will be remembered for the kindness and compassion of New Zealanders and the leadership of Ardern.

Examples of this, he said, were leading New Zealand through the Christchurch terror attack, the eruption of Whakaari/White Island and the Covid-19 pandemic.

"At the beginning of the term I would never have guessed that I would be the Immigration Minister who closed the border," he said.

"I mean, I knew we were in coalition with NZ First, but it still never crossed my mind."

He said some of his greatest achievements as a minister was putting in place legislation, which saw the extension of paid parental leave to 26 weeks, and increasing the refugee quota.

He was also proud of his work around temporary work visas.

But he also spoke of the difficulties trying to push through the Employment Relations Amendment bill, which was – at times – held up by NZ First.

"If stakeholder relationships can be hard to manage, they've got nothing on coalition relationships."

Lees-Galloway also said advocating for Palmerston North – his electorate – had been one of the most rewarding parts of his job.

Clare Curran: 'I was made a public spectacle'

Former Broadcasting Minister Clare Curran said in her speech that Parliament could be a toxic place.

"Mine has not been an easy ride," she said.

Curran said it was with "pain and relief" she gave her speech.

She said she had made a "public spectacle in the House".

She believed that politicians focused on attacking each other, rather than focusing on policies.

"The objective is to catch people out and take them down."

Politicians, she said, "are not prey".

She told the press gallery that they are neither judge nor jury.

Curran also called out RNZ, who she said was not properly doing its job in holding media and MPs to account.