Almost 100 extra workers on a $6.7 billion tunnel project have lost their jobs as the fight over who pays landfill fees continues to rage.

Australian Workers’ Union Victorian branch secretary Ben Davis said the West Gate tunnel project workers lost their jobs on Wednesday.

“They were made redundant today. About two-thirds of them were white collar and 25 were construction workers,” Mr Davis told AAP.

“The state of uncertainty over PFAS-contaminated soil has led to another round of job losses.

“There needs to be a resolution on where to transport and store the PFAS-contaminated soil – it needs to be sorted now.”

For every day this dispute drags on, Mr Davis said, more jobs could be lost.

“The three parties need to roll up their sleeves. Big companies are using workers’ jobs as cannon fodder and it’s disgusting,” he said.

The workers are caught in a fight linked to cost increases and a landfill levy for soil stored along parts of the West Gate Freeway.

The builders have permits from the state’s environment watchdog to take some of that soil to landfill but have chosen not to, Mr Davis said.

Toll giant Transurban, which is leading the construction of the tunnel, said the CPB John Holland Joint Venture has options to keep staff on.

“We’re extremely disappointed to learn that despite our efforts to support a path forward on the project, they’re continuing to make changes to their workforce,” a company spokeswoman said on Wednesday.

Companies CPB and John Holland reportedly told the state government up to 600 project workers could be cut by the end of June.

Earlier this month about 100-120 workers on the project were sacked while the squabble over tip fees flared up.

“There is no reason whatsoever for Transurban’s builders CPB and John Holland to sack these workers,” a state government spokeswoman said on Wednesday night.

“While businesses across Australia are going to extraordinary lengths to keep staff on – Transurban’s builders sacking more people because they can’t resolve a petty dispute – is disgraceful.”

The government signed the project deal with Transurban, which has then contracted work to companies CPB and John Holland.

The tunnel is due to be finished in 2023, a year behind schedule.