By Jacob Shteyman in Canberra

Coles has hit out at Canberra for “politicising” cost-of-living issues to attack supermarkets and deflect difficult questions about inflation.

The grocery giant’s chairman James Graham told shareholders Coles was well aware of economic pressures faced by customers and was continually seeking ways to respond and build customer trust.

“In this context it has been disappointing to see how cost-of-living issues have been politicised and targeted at supermarket operations,” he told the company’s annual general meeting on Tuesday.

Coles and rival Woolworths have been in the sights of politicians and the consumer watchdog after a damaging year for the sector’s reputation.The Australian Competition and Consumer Commission launched legal action against the pair in September, alleging they misled shoppers by substantially raising prices before marginally lowering them on hundreds of popular products and passing it off as a discount.

But Mr Graham said the fluctuations were the result of price rises from suppliers and not a deliberate attempt to fleece consumers.

“The matters raised by the ACCC relate to a period of significant inflation leading to a sharply increasing level of supplier cost price increases,” he said.

“The subsequent discounts offered to customers on these items were the result of promotional investment by the supplier and Coles which delivered a reduction in the shelf price at a time when households were under significant cost-of-living pressure.”

Coles and Woolworths together control about two thirds of the grocery sector and have been accused by a separate Senate inquiry of abusing their market power to the detriment of shoppers and suppliers.

The coalition has threatened to introduce laws that would allow the major chains to be forcibly broken up.

In response to a question from a shareholder about how Coles was working to minimise regulatory risks, Mr Graham said the company was committed to ensuring all parts of the business do the right thing.

“We are fully co-operating with all of the inquiries that are being undertaken,” he said.

“But I do think there has been a wider ambition of some behind those inquiries to seek to perhaps provide answers to more difficult issues which have been arising from, as I mentioned, inflation, which has been seen at earlier times.”

Coles executives will front the ACCC’s supermarkets inquiry later in November.

Chief executive Leah Weckert said Coles was increasingly concerned about a rising trend of threatening situations directed at front-line staff over the past 12 to 18 months.

“We are working with industry to address this worrying trend happening across many retailers, while continuing to roll out de-escalation training to our team members to help reduce the number and severity of incidents,” she said.

Shareholders will also vote on a resolution to stop sourcing farmed salmon from Tasmania’s Macquarie Harbour, where aquaculture practices threaten the existence of the Maugean skate, a prehistoric ray estimated to number between 40 to 120 in the wild.

Environmental advocates Neighbours of Fish Farming will confront the board on the issue, but the group’s president Peter George applauded Coles for at least promising to reduce the amount of salmon sourced from the harbour.

Mr George said Coles and Woolworths have been put on notice about their contribution to the decline of the skate.

“They’ve been given an opportunity to act to save an extinction and the health of the harbour, they can’t deny they didn’t know about it,” Mr George told AAP.