Father John Craddock is beginning the service.

The entrance music is Chariots of Fire.

Former Labour MPs Clayton Cosgrove and Maryan Street also in attendance.

Anderton's grandchildren are the pallbearers.

Te Kahu Whata-a-rangi Anderton-Graham carries a photograph of Anderton.

The grandchildren are lighting candles to represent justice for all and peace for humankind.

Former Prime Minister Jim Bolger and former National MP Philip Burdon are also attending.

Chris Anderton, Jim's son, is giving the first eulogy. His voice is breaking as he thanks the family.

He says his dad was known for his go-karting exploits growing up in Auckland's Grey Lynn. He was also a member of a notorious window-breaking gang that broke some windows in 1948. "There were no prosecutions. Dad, I think it's safe to say you got away with it."

He was also an organiser who loved to win, no matter what the game was, and was an avid reader who interpreted all of Spike Milligan's voices.

"He instilled a love of fishing in my younger brother ... you could say he was overqualified as the Minister of Fisheries."

He taught the joys of cricket, "a game we played and watched together endless times".

He also "loved pies".

"He had a great love of music and introduced us to his idols Bob Dylan, The Beatles and Simon and Garfunkel to name a few. He loved to harmonise."

He said Jim Anderton has a strong moral compass, whether it was over the Bastion Point occupation, opposition to the dawn raids, the deep sense of injustice over the effects of neoliberalism, or fighting for the ChristChurch cathedral.

He is now in the executive in the sky where he will guide Jacinda Ardern to "free dental care".

Fighting tears, Chris Anderton started singing Tom Petty's I Won't Back Down, adding that he was sad that his father would not be there to harmonise.

Brenda Hill is giving the second eulogy.

She said he was a loving and caring member of the family.

"The time's we all spent together over the years have been wonderfully full ... We have laughed with you. We have laughed at you, as it was a competition to get one up on you."

"It is the time we spent together at Christmas and over the summers that were extremely memorable, you with your Santa hat on with a running commentary ... Boxing Day was saved for your passion of cricket, wrestling the remote from mum or the girls, or with your ever-present radio ... Backyard cricket matches were legendary. There was much screaming and yelling, and you didn't like to get out."

Chess was also a huge battle every game. "Jim never got out-witted ... he may have only conceded being beaten only twice."

She also paid tribute to his love of music.

Hairbrush, a radio, a phone and his glasses were the items he never left home without, but consistently left them in movie theatres and taxis.

He was also passionate about the garden or mowing the lawn. "The roses were a delight to you. You'd pick them for mum and take them inside."

"You have been an inspiration in education for the whole family ... in the end broadening our knowledge and our horizons. You have continuously challenged everyone to do better."

"Jim always made every grandchild individually important. He was a great man who will be greatly missed by everyone who came into contact with him."

She said he created a centre of caring and sharing for anyone.

She said his widow Carole will find it hard to fill the gap that is now in her life, but she and others will do their best. "Thank you so much for sharing your life with us."

Brian Roughan is giving the scripture reading. This is followed by singing of The Lord's My Shepherd.

Former Deputy Prime Minister Jim Anderton is being farewelled in the city he served as the Sydenham and Wigram MP from 1984 until his retirement from Parliament in 2011.

Prime Minister Jacinda Ardern is attending today's funeral, alongside Finance Minister Grant Robertson, Labour Party general secretary Andrew Kirton, and Council of Trade Unions general secretary Sam Huggard and Cabinet Minister Megan Woods, Anderton's successor in Wigram.

Ardern has called Anderton a man of "huge integrity, huge compassion, a man who stood strongly for what he believed in and gave 40 years of service both in local government and central government".

"He will be sadly, sadly missed by the Labour movement and by all his friends and family."

Jim Anderton's son Chris says he has been overwhelmed with support after his father's death at the weekend.

Writing on Facebook this morning, Chris Anderton thanked people for the messages of supported he had received: "They uplift me."

Anderton was two weeks shy of his 80th birthday when he died peacefully in Christchurch.

Close friend and former MP Matt Robson, who served in Parliament from 1996 to 2005 with Anderton's Alliance Party and then the Progressive Party, will be one of the speakers at today's funeral.

Anderton's legacy has been praised since his death, from his principled stance in 1989 when he left the Labour Party in protest over Rogernomics and the sale of BNZ, to his championing MMP as leader of the Alliance.

His work in the Helen Clark-led Government included helping to set up KiwiBank, the NZ Superannuation Fund, paid parental leave and several regional development initiatives such as the Marlborough Wine Research Centre.

After he retired, he served as chair of the Stadium Trust and pushed for the rebuild of the ChristChurch Cathedral.

Last year Anderton was made a Companion of the New Zealand Order of Merit for services to Parliament.

He will be buried on Waiheke Island on Saturday.