Workers go on strike at Coles warehouse in Melbourne

The striking workers set up a picket in Somerton, in Melbourne's north, from 6am (AEST) on Tuesday with numbers expected to swell later in the day.

The indefinite strike comes after a dispute over conditions.

Workers took the indefinite strike action after Toll Holdings, which manages the warehouse, refused to budge on negotiations, National Union of Workers state secretary Tim Kennedy said.

"What we have here at Somerton is a situation where these workers are not treated equally in comparison to other Coles warehouse facilities that supply Coles Supermarkets," Kennedy said in a statement.

"If a Coles shift worker in a Coles warehouse gets paid a shift loading ... then Toll shift workers doing exactly the same work in a Coles warehouse supplying Coles supermarkets should also be paid a shift loading."

Kennedy said Coles should not outsource to a company that didn't provide for standard conditions.

"The workers have voted overwhelmingly to take this strike action as they are sick of Coles ignoring their rights."