A shopper raised the alarm after a conversation at Marks and Spencer in Shoreham and took his complaint to the highest level.
Dr Andy Moore, of East End Lane, Ditchling, told chief executive Marc Bolland he was ‘both surprised and horrified’ to discover large amounts of unsold food were reportedly taken to landfill sites on a regular basis.
He also alerted East Worthing and Shoreham MP Tim Loughton and Brighton Pavilion MP Caroline Lucas.
But Marks and Spencer said there had been a misunderstanding between Dr Moore and a store employee.
“Our Shoreham store, like all of our stores, does not send any food waste to landfill,” a spokesman confirmed.
“In fact, we can confirm that as part of our Plan A commitment to reduce waste, since 2012 we have been a zero-waste to landfill business. Since achieving this, we have continued to work really hard to reduce food waste.
“Where there is waste, most of it (89 per cent) is sent to anaerobic digestion, a process that turns food waste into electricity, with the remainder being re-used in other ways, for example through our partnership with FareShare, the UK charity supporting communities to relieve food poverty.”
Dr Moore suggested food approaching its sell-by date was sold to staff at a nominal price as a goodwill gesture.
Other products could be channelled to the needy through food banks, he added.