Supermarket giant Coles is reportedly cutting 600 jobs at the company's Melbourne headquarters to lower prices for customers.

According to media reports, the cuts will be made across departments including payments, accounts and IT, as part of a bid to free up funds to help reduce food and liquor prices.

One union said there had been no official announcement from Coles, which has not commented on the reports.

Ingrid Stitt, from the Australian Services Union (ASU), has demanded information from the company saying the workers have been left in limbo without an official announcement.

"It's a significant number of jobs that will be lost and worryingly, if the media reports are accurate, it looks like some of these jobs might be off-shored," she said.

"We obviously want to know what steps are going to be taken to try to find alternative employment for people and what training opportunities might exist for some of the workers that have been impacted."

Ms Stitt said she was worried about the increasing trend to send jobs off shore.

"We've had a series of really bad announcements, not just in manufacturing and blue collar jobs in Victoria lately but many white-collar professional-services jobs," she said.

"We're not really seeing a plan to address that in terms of attracting the jobs of the future to Victoria.

"You really do have to question where our kids and our grandkids are going to be working in the future."

Opposition Leader Daniel Andrews said the state needed a jobs' plan.

"We need a plan to create jobs," he said.

"Every job is worth fighting for and yet again another day, another industry, more workers, 600 workers, face an uncertain future."

ACTU president Ged Kearney called it "devastating news" and said once again jobs are disappearing under a coalition governments at federal and state levels.

"You could also ask where are these jobs going? Are they going offshore," she asked.

"Where are all these jobs that we were promised would come from this Government?

"We have start asking the question where are the jobs coming from Mr Abbott?"