Loved and loathed, Labour MP and former Speaker of the House Trevor Mallard is off to Ireland soon as New Zealand’s Ambassador, 38 years after he was first elected to Parliament.

Today is his last in the halls of power and caps off a memorable career full of highs and lows, each with its own quirks, for a politician described as everything from "attack dog" to "father of the house".

Mallard will deliver his valedictory speech today at about 4.30pm. It will be livestreamed on the Herald website.

Mallard was first elected as MP for Hamilton West in 1984 under David Lange's Fourth Labour Government before losing in 1990. Three years later he returned, winning the Pencarrow electorate - now Hutt South.

Under the fifth Labour government of Helen Clark, he went on to hold multiple ministerial portfolios, including decent stints in education and sport.

Under Prime Minister Jacinda Ardern's leadership he stepped into the role of refereeing political debate as Speaker of the House.

Prime Minister Jacinda Ardern watching then-Speaker Trevor Mallard testing the slide on Parliament's new playground, Wellington, in 2019. Photo / Mark Mitchell

At each stage of his career though, Mallard made sure he was never far from the limelight.

Among his more silly moments include promoting the restoration of moa in Wainuiomata, through to blasting Barry Manilow's hit Macarena through loudspeakers at Covid-19 protesters.

His more controversial moments include a scuffle in 2007 with a National MP that landed him in court, and falsely alleging a political staffer of raping another staff member, comments that ended up costing the taxpayer $330,000.

Senior Labour Minister Chris Hipkins said Mallard was someone who he had "enormous respect for who I am enormously frustrated by at times".

"I regard him as a very good friend, and someone who I'm incredibly grateful to because he has provided me with, through my working life, a number of incredible opportunities that I will always appreciate."

Mallard held 13 ministerial portfolios, including lengthy stints in charge of education and sport and recreation.

As Speaker he instigated a review of bullying culture, and made the halls of power more child and dog friendly.

But he was never far from controversy, and his antics during the Covid-19 protests - including setting the sprinklers on them - again drew motions from the Opposition of no confidence.

Today a court found Mallard "unreasonable" and "irrational" in trespassing a former deputy prime minister, NZ First leader Winston Peters, from Parliament during the Covid-19 protests.

A fitting "epitaph" is how National MP and fierce parliamentary rival Chris Bishop called the court ruling. "Good" is also what Bishop said after he heard Mallard was resigning as Speaker.

Bishop was even less conciliatory today, his departing words: "See you later."

He also noted the "symmetry" of Gaurav Sharma's resignation this week from his Hamilton West seat, which Mallard came into Parliament on 38 years ago.

"One Hamilton West MP departs out the back door as another former MP Hamilton West MP departs out the back door."

Mallard will be replaced on the list by Soraya Peke-Mason - and that will mean that for the first time ever, Parliament will have as many women MPs as men.

Long-time candidate Peke-Mason will also become Labour's latest Māori MP from the Rātana Church. The church has in the past been critical of its relationship with the party and low ranking of its members implying it was taking their support for granted, including Peke-Mason.

After his final day in Parliament today, Mallard is expected to begin his posting in Dublin in January 2023.