Simon Roberts, chief executive of the supermarket group, said it is working to reduce costs across its operations amid continued inflation.
It came as the retail giant revealed that like-for-like sales, excluding fuel, declined by four per cent over the 16 weeks to June 25, compared with the same period last year.
Sainsbury’s hailed a “good” performance in its grocery business, which saw sales dip 2.4% against levels from last year, which had benefited from pandemic restrictions on other parts of the retail sector.
Chief executive Mr Roberts said: “We really understand how hard it is for millions of households right now and that’s why we are investing £500 million and doing everything we can to keep our prices low, especially on the products customers buy most often.
“We’re working hard to reduce costs right across the business so that we can keep investing in these areas that customers care most about.
“The progress we are making on improving value, quality, innovation and service is reflected in our improved grocery volume market share.
“The pressure on household budgets will only intensify over the remainder of the year and I am very clear that doing the right thing for our customers and colleagues will remain at the very top of our agenda.”