By Adrian Black

Empty supermarket and bottleshop shelves in multiple states could soon be restocked, but the workplace stoush that sparked the shortages is far from over.

The Fair Work Commission has ruled picket lines led by United Workers Union members at four key Woolworths’ distribution centres are unlawful and the union should inform participants within hours.

Warehouse workers and the retail giant have been locked in tense negotiations for months over pay and conditions, including an algorithmic management platform the union said put employees at risk.

In handing down a bargaining order, commission deputy vice president Gerard Boyce said the union had failed to meet its good faith requirements under the Australian workplace laws.

“The conduct is not part of any protected industrial action,” he told the hearing.

“It’s not the simple removal of labour from the employer.”

The actions had unfairly blocked warehouse workers and truck drivers who wanted to get into the work sites, the commissioner found.

Picketing had also taken place at distribution centres not involved in bargaining talks, which amounted to unprotected industrial action.

The major supermarket closed the centres, lacking the staff to operate them safely, but claimed workers wanting to return had been blocked by union members.

Sixteen days of industrial action has emptied thousands of supermarket and bottle shop shelves in Victoria, NSW and the ACT and cost the supermarket chain at least $50 million.

Woolworths lawyer Marc Felman said the distribution centres were the “heartbeat” of its supply chain as he argued the picketing amounted to unfair conduct in their bargaining.

“They should be free to continue to come to an agreement in an orthodox way without the gun to the head of an obstructive picket,” Mr Felman told the hearing in Melbourne.

Outside of the hearing, United Workers Union secretary Tim Kennedy said members were demanding better pay and changes to an algorithmic performance management framework that put workers at risk.

“Woolworths can step forward and show some dignity and respect to their workers … so they can plan for Christmas,” he said.

The union said Woolworths had insisted on holding separate talks at each of the four warehouses in question, stifling the bargaining process.

But the retail giant’s lawyers claimed there had been picketing at warehouses not involved in talks, which amounted to unprotected action.

Mr Kennedy said negotiations were ongoing and the Fair Work hearing was a distraction.

“I think the problem is that Woolworths are used to just saying ‘it’s our way or the highway’, whether that’s to farmers, suppliers or customers,” he said.

Woolworths said the “obstructive” pickets undermined the bargaining process and were not protected under Australian law.

“You are able to peacefully protest and take protected strike action,” Mr Felman told the commission hearing.

“What you can’t do is be obstructive about it.”

It could take days for shelves to be restocked to normal levels.