It comes as one protester said her car tyres were slashed, while others were hospitalised after being struck by trucks, the National Union of Workers alleged. Police were called over one threat. Loading Chemist Warehouse director Damien Gance said he ''expressly and unequivocally'' denied allegations of any violence or unlawful conduct directed at the picket line. Mr Gance also claimed the strike had not affected supplies in its stores. ''We will continue to work tirelessly to ensure that this industrial action has little to no effect upon our stores and in turn our patients and customers,'' he said.

The workers have been on indefinite strike since March 12 at large distribution centres at Somerton and Preston in Victoria and Eagle Farm in Queensland. The strike at Chemist Warehouse's distribution centres started on March 12 Credit:Ben Schneiders The centres are vital in supplying Chemist Warehouse and My Chemist stores across Australia. NUW national secretary Tim Kennedy accused Chemist Warehouse management of condoning violence at the picket lines. ''We've seen cars and trucks drive deliberately into striking workers, with several workers injured and requiring hospital admission,'' he said.

''It is shameful to witness such a large company completely disregard the rules of protected industrial action and show such little regard for their workers' safety." Mr Gance said Chemist Warehouse office staff - who are not part of the dispute - had been told to avoid any conduct that could inflame the situation. ''We have repeatedly implored all our staff to exercise humility, civility and humanity in any interaction with the picket, this in the face of aggressive, derogatory and offensive behaviour from others,'' he said. ''To my knowledge our people have met the standards we have set.'' On Friday, a union protest at the Preston site was greeted with a layer of manure out the front of the building. Striking workers and unionists outside Chemist Warehouse's Preston distribution centre on Friday. Credit:Justin McManus

Workers at the distribution centres are seeking much higher pay - of up to 25 to 30 per cent - to bring wage rates in line with Chemist Warehouse’s competitors. Workers are on strike over pay and job security Credit:Ben Schneiders Permanent workers are currently paid about $24 an hour. They are also seeking much greater job security through significant changes in the use of labour hire and casual labour. According to the NUW, only about 20 to 25 per cent of workers in the distribution centres are permanent. The union want to lift that to more than 70 per cent.

The Chemist Warehouse group - which also trades as My Chemist - has skirted industry regulations that restrict ownership of pharmacies to pharmacists themselves and store location rules. To bypass the rules, Chemist Warehouse operates as a complex franchise network - a web of partnerships between the founding families that own it and individual pharmacists. Its co-founders Jack Gance and Mario Verrocchi are now both on the Financial Review’s list of the 100 wealthiest Australians. Both are estimated to be worth more than $800 million each. Mr Kennedy said there has been little progress in talks between the company and the union and accused the company of adopting a ''go-slow strategy''. Empty shelves at an inner Melbourne store Credit:Ben Schneiders

"This is no ordinary industrial dispute. This is a seminal struggle between ordinary working people fighting to improve their lives, and some of the richest people in this country,'' he said. Mr Gance defended its pay rates and said it had not commented until now as ''we believe these negotiations are best conducted in private'' to ensure the best results for all. ''Staff in our distribution centres are currently remunerated well above award rates,'' Mr Gance said. ''We have made a good offer to our employees which will mean that over the course of the agreement they will continue to move further and further above award rates.'' In 2016 Chemist Warehouse was forced to pay back $3.5 million to nearly 6000 in-store staff after a Fair Work Ombudsman audit uncovered it was underpaying them.

The discount chain had not been paying staff for training done outside of work hours. Do you know more? Contact us securely via Journotips