The family of a scaffolder who lost both arms after an electric shock at work is fighting for proper compensation, claiming he's being underpaid by up to $14,000 a year by ACC.

Father of three Jahden Nelson suffered a heart attack, internal injuries and burns to 25-35 per cent of his body eight weeks ago during a workplace accident in West Auckland.

The double amputee faces months in hospital and years of surgery and rehabilitation.

His former employer Supercity Scaffolding had treated Nelson as a self-employed contractor. ACC has done the same, meaning he is now receiving hundreds of dollars a week less than he'd be eligible for if treated as an employee.

Advocates say the situation is unfair. They plan to challenge ACC's determination and say a law change is needed to protect vulnerable workers like Nelson and his family.

"This guy has suffered a devastating workplace injury and now he faces the unfairness of being ripped off by the system," Te Atatu MP Phil Twyford told the Herald.

"He earned $27 an hour - barely more than minimum wage. He had to provide all his own tools. He received no sick pay and no holiday pay.

"To rub salt in the wound he's now getting the lowest possible amount in compensation because the law absurdly treats him as a contractor. It's wrong and it has to change."

Te Atatu MP Phil Twyford says the injured scaffolder has been "ripped off" by an unfair system. Photo / NZME

Nelson, 28, was critically injured while dismantling scaffolding at a Massey worksite in April.

It's believed he was holding a steel pole when it touched low-hanging overhead lines. Witnesses saw a "fireball" erupt when the electric current ripped through Nelson's body before he collapsed.

He has spent nearly two months in hospital and undergone about 30 operations.

His mother Toni Paikea had to make the agonising decision to amputate her son's arms in consultation with clinicians.

Toni Paikea's son Jahden Nelson suffered an electric shock in a workplace accident in Massey in April. Photo / Alex Burton

Nelson's life initially hung in the balance, but he is now out of ICU and receiving treatment in Middlemore Hospital's burns unit.

Paikea told the Herald her son's dramatic recovery amazed physicians.

His badly damaged kidney had regenerated and he was no longer receiving dialysis, she said. He had undergone extensive grafting and was now "mostly closed and covered with his own skin".

He was awake, coherent and responsive, and no longer required assistance to breathe.

"We're still praying and hoping for a miracle," Paikea said.

"I cried beside him and said, 'I had to make those decisions because I wanted you alive'. He said, 'I want to see my babies. I don't want to die'."

Paikea said her son's three young children were finally allowed to visit him at the hospital last month, yelling, "Dad, dad, dad".

"In their eyes there is nothing different about their dad, they're just wanting their dad home."

She was "disheartened" that Nelson was being treated as a contractor and wanted him to receive what he was owed.

Scaffolder Jahden Nelson, 28, remains in hospital after a worksite accident in Massey in April. Photo / Supplied

However, the fight for compensation was not just for her son, but all affected workers, she said.

Employment lawyer Hazel Armstrong has taken up Nelson's case pro bono. She said in her opinion her client had been deemed a contractor by Supercity Scaffolding for "tax purposes".

But he had not signed a contractor's agreement and for all intents and purposes was an employee of the company, working set hours of 7am to 5pm five days a week, Armstrong believed.

Toni Paikea believes her son Jahden Nelson was holding a scaffolding pole at this Massey worksite which touched overhead wires. Photo / Supplied

Armstrong's opinion was Nelson did not choose to be a contractor, or to forgo the financial benefits and protections that come with being an employee.

"He didn't select it, he just wanted a job. He wasn't happy that he didn't get paid for statutory holidays but he didn't have a choice."

Armstrong planned to seek an Employment Relations Authority determination about Nelson's actual employment status then ask ACC to review its compensation assessment.

She also wanted the law changed to enable ACC to properly assess the employment relationship of vulnerable workers who were injured on the job - rather than simply relying on the classification made by employers - often to reduce company costs.

Twyford has already raised the matter with Workplace Relations Minister Michael Wood and ACC Minister Carmel Sepuloni.

West Auckland scaffolder Jahden Nelson, 28, pictured with his baby daughter. Photo / Supplied

"This is not the fault of ACC," Armstrong said. "They're just following what the legislation says. But the legislation does not give them enough discretion to ascertain the reality of the employment relationship."

Supercity Scaffolding director Claire Attard said she was unaware of Nelson's ACC claim but said the company supported all its workers.

The company had continued paying Nelson for 40 hours a week since the accident "to help him through this difficult time".

ACC acting chief operating officer Gabrielle O'Connor said the agency aimed to help all New Zealanders. However, it was bound by the Accident Compensation Act.

"ACC provides support in a variety of ways, such as paying for treatment, rehabilitation, home help and financial compensation. All this can have a significant impact on a person's wellbeing. We encourage people to talk to us about the options available."

Nelson's accident is under investigation by WorkSafe.

A givealittle page has raised more than $66,000 to support his recovery.