UPDATED 3.40PM: Former union boss Helen Kelly has been remembered as a person who fought to empower others at a memorial service at a packed Michael Fowler Centre in Wellington.

There was a sombre mood in the capital, as hundreds of people streamed into the Michael Fowler Centre to remember Kelly.

Photos from various moments of her life were shown to the crowd ahead of the ceremony, and an enormous bouquet of flowers took centre-stage.

The order of service was coloured bright red, and on the front was a black and white photo of Kelly protesting with a loud speaker.

Kelly, 52, the former Council of Trade Unions president of eight years, was diagnosed with terminal cancer in February 2015, and died two weeks ago. 

Current CTU president Richard Wagstaff told the assembled mourners that Kelly stood firm for what she believed in, and made sure others stood with her.

"One of our brightest has fallen," he said.

"This room, and this country, is full of people who will miss Helen because she gave them the spirit they needed to stand up, dust themselves off and keep fighting for what's right." 

A family service was held last Friday for Ms Kelly who died on October 14 aged 52 from lung cancer.

"We have been so moved by all of the support," husband Steve Hurring said.

He said Ms Kelly was a kind, loving, caring, generous, wise, beautiful courageous, inspirational, hard-working and warm-heated person.

Mr Hurring spoke about Ms Kelly's childhood as a daughter of union boss Pat Kelly, who passed away in 2004.

He said it was a beautiful childhood.

Ms Kelly and brother Max recalled their father taking them on a Sunday morning walk around the waterfront yarning with the wharfies, some times being pulled along in a trolley made from an apple box.

The conversation around the family's dinner table was invariably political.

Mr Wagstaff said Ms Kelly loved people.

"She wanted people to be empowered and she did empower people," he said.

He said Ms Kelly was changed forever by the Pike River mining disaster where 29 men died.

She was deeply affected by that experience, believing forcing anyone to work in an unsafe environment was the ultimate sign of disrespect and disregard for people, he said.

She went on to expose the death rate in the forestry industry and led private prosecutions taken by the CTU.

Mr Wagstaff said the union had had time time to prepare for her death "but coming to terms with it has been tough".

She was too young to die and had so much more to give, he said.

"We know the best way to honour her memory is to continue to build a strong union movement," he said.

Ms Kelly was the first woman to lead the CTU.

Maxine Gray from First Union also spoke to the hundreds of people inside the venue.

"We will cry for you, Helen, even though you told us not to, and then we live for you, and we will honour you."

Labour MP Trevor Mallard had those gathered in fits of laughter as he joked about the two bossy Helens he's had in his life.

He then broke down, as he read a message from Helen Clark.

Trevor Mallard said Helen Kelly will be remembered again when there's been a whole year without a farm worker dying, when a normal contract is a 40 hour week, and when the Living Wage is for all.

"Helen will be remembered when medicinal cannabis is a matter for sick people and their doctor, and when Pike families get to bury their dead."

Actress Robyn Malcolm paid tribute to her 'mate', in a short speech followed by a powerful video about work place deaths and need for health and safety reform.

She said she's mourning the loss of a friend, who she first met as a trade unionist.

"Thank God for the New Zealand trade union movement, and for Helen Kelly."

Additional reporting by NZ Newswire