Woolworths say the ongoing strike at several of its distribution centres has cost it $50 million – and costs will keep mounting.

The company revealed the cost in an update to the ASX on Tuesday, as it also emerged it had filed an urgent application with the Fair Work Commission to stop union members blocking access to its distribution centres.

Both sides appear to be digging in as the damaging strike nears the end of its second week, with picketers vowing to continue their around-the-clock presence at four Woolworths warehouses until a pay deal is reached.

United Workers Union members have blocked all entrances to a key distribution centre in suburban Melbourne after Woolworths announced plans to reopen.

Plans to bring in staff on Monday never eventuated, but picketers at the Dandenong South site turned away logistics trucks trying to enter.

Two other sites in Victoria and one in NSW are also affected by the industrial action.

Woolworths Group filed an urgent application with the Fair Work Commission on Tuesday.

“The application comes after the UWU refused to give any assurance of safe passage for team members seeking to return to work at our Melbourne South Regional Distribution Centre yesterday and this morning,” it said.

The application to Fair Work alleges a breach of the Good Faith Bargaining requirements in the Fair Work Act.

The matter has not yet been listed for hearing.

The supermarket giant confirmed it would again try to reopen the distribution centre again on Tuesday but would follow advice from Victoria Police on whether it was safe.

The union is also demanding no enforceable performance standards, which Woolworths said would would preclude its ability to manage productivity.

“We sincerely apologise to all of our customers for the inconvenience caused by the inconsistency of supply across some product lines in some of our stores,” Woolworths Group chief executive Amanda Bardwell said.

As the dispute has ground on, supermarket shelves across Victoria have been stripped, in scenes akin to the Covid-19 pandemic.

“Until the industrial action is resolved, a further impact to sales is expected. The full financial impact at this stage is unknown,” Woolworths told the ASX.

“It will be dependent on the duration and extent of the ongoing industrial action across the affected sites, and the time taken to rebuild inventory ahead of the Christmas trading period.”

Empty shelves at a Woolworths in inner-city Melbourne on Monday. Photo: AAP

The company says most of the workers at the Dandenong South centre are not union members and want to return to work.

“Our customers are facing increasingly empty shelves, another union has endorsed our deal, and we are still at the negotiating table with the UWU,” a Woolworths spokesperson said on Monday.

“As long as they continue to block access to our site, our customers will continue to face shortages on shelves in Victoria.”

The company and union returned to the negotiating table on Monday.

“We are hopeful of a breakthrough because our workers deserve to be safe at work,” UWU national secretary Tim Kennedy said.

Woolworths told the ASX the UWU demands would mean pay increases of more than 25 per cent over three years.

“[This would be] materially above inflation, at a time when Woolworths Group is actively working to keep food and groceries
affordable for customers facing ongoing cost-of-living pressures,” it said.

The company said it had used “a range of contingency plans” to keep stores stocked, including building inventories and even having some suppliers deliver direct.

“However, due to the extended disruption, some Woolworths supermarkets in Victoria, ACT and NSW are experiencing stock-flow limitations on some lines, impacting product availability of ambient, chilled and freezer lines for customers,” the ASX update said.