Looks like some M&S stores are clearing out some stock in their food halls, such as 6x 250ml cans of Coca Cola Zero for just £1.05, 2L Diet Pepsi for just 55p and small 330ml bottles of Sprite and Dr Pepper Zero for just 45p.
Additionally, a bunch of individual ice creams for between 25p - 47p such as Flake single ice creams, Strawberry and Salted Caramel Cornetto's M&S Orange Lollies for 25p etc. Plus selected sweets, biscuits, cakes and crisps for up to 75% off
Likely these deals are national but stocks vary store to store. These were found at the Worcester High Street store, but did see price tags at the Birmingham City Centre store, though it was quite picked over.