M&S is removing best before dates from loads of fresh fruit and vegetables to try to cut food waste.
Supermarkets are beginning to end use-by dates to cut down on food waste.
Morrisons has scrapped the dates on its own-brand milk and the Co-op has done the same for yoghurt, while many retailers have stopped putting the dates on vegetables.
Now M&S is scrapping best before dates on more than 300 fruit and veg - around 85% of all its produce.
This includes foods like apples, potatoes and broccoli, which are often thrown away before they get eaten.
UK households throw away around 6.6million tonnes of food a year, according to research from food waste experts WRAP.
That is the same as 550,000 double-decker buses, or 440,000 elephants.
Best before dates are part of the problem, as often food can safely be eaten beyond the point listed on packaging.
Now M&S is replacing best before dates with a secret code that shoppers won't be able to work out.
This code lets supermarket staff remove food that is really going off, but otherwise lets shoppers buy things using their common sense.
M&S said all its supermarkets would make these changes this week.
The supermarket wants to halve its own food waste by 2030, and plans to give away all of the edible food it chucks out by 2025.
It has already been giving away food to charities - with more than 44million meals donated since 2015.
M&S director Andrew Clappen said: "We’re determined to tackle food waste – our teams and suppliers work hard to deliver fresh, delicious, responsibly sourced produce at great value and we need to do all we can to make sure none of it gets thrown away.
"To do that, we need to be innovative and ambitious - removing best before dates where safe to do so, trialling new ways to sell our products and galvanising our customers to get creative with leftovers and embrace change."
WRAP director Catherine David said: "We’re thrilled to see this move from M&S, which will reduce food waste and help tackle the climate crisis."
Supermarkets have also agreed to sell most fresh fruit and vegetables loose rather than packed in plastic , to help the environment.
All major supermarkets have signed up to guidelines by sustainability organisation Wrap to sell loose produce by 2025.
Apples, bananas, broccoli and cucumber will be among the first to be sold without plastic wrapping.
Other items that will soon be sold with no packaging include aubergines, avocados, carrots, onions and peppers.
WRAP thinks 80% of fruit and vegetables can be sold with no wrapping.
It estimates this will save more than 21,500 tonnes of plastic being thrown in the bin every year.
Earlier this month The Mirror reported that a man with a "titanium belly" has gone viral after experimenting with how far he can stretch the shelf life of foods - including eating a fried egg 73 days past its best before date when another the same age had turned green.
