Australia’s biggest supermarket chain, Woolworths, says it has lost $50m in grocery sales since the start of industrial action that has disrupted the flow of goods into some of its stores.

More than 1,500 Woolworths warehouse workers have been on strike since 21 November, seeking better pay and safety on the job. Industrial action has affected up to five distribution centres, impacting supplies in some stores in Victoria, New South Wales and the ACT.

Woolworths told shareholders on Tuesday its revenue was being affected.

“Since the start of the industrial action, Australian food sales have been negatively impacted by approximately $50 million to date (up to 2 December),” Woolworths said.

“Until the industrial action is resolved, a further impact to sales is expected.

“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.”

It comes as Woolworths filed an urgent application with the Fair Work Commission for a circuit-breaker to ban warehouse workers from blocking their distribution centres.

“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 (MSRDC) yesterday and this morning,” Woolworths said in a statement on Tuesday morning.

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 strike action has seen supermarket shelves across Victoria stripped, with scenes akin to the early Covid-19 pandemic lockdowns.

One store, on Collingwood’s Smith Street, had most of its toilet paper aisle emptied along with large portions of its bread and fridge sections.

Those ordering grocery deliveries were also warned to allow substitutions to ensure they receive the products they want.

No product limits were in place at the time apart from eggs, which have been rationed for months following bird flu outbreaks in NSW and Victoria.

It’s believed the strike is yet to affect Victorian farmers, whose produce normally hits supermarkets closer to Christmas – but items such as nappies, toilet paper and drinks have been affected.

The decision to go to Fair Work follows the company and union returning to the negotiating table on Monday.

The United Workers Union national secretary, Tim Kennedy, said warehouse workers had engaged in good faith negotiations for almost seven months and have raised concerns about a “punitive” productivity framework imposed on workers.

“They are also fighting for a fair pay rise,” Kennedy said.

Shares in Woolworths were trading slightly higher in morning trade in a broadly positive market.

– Australian Associated Press contributed to this report