Found this bulk pack at random by a till in Llandudno Junction Tesco (North Wales). Assuming it is a nation wide deal. Equates to 20p a can - cheaper than Mixxed Up (Lidl) and Euro Shopper ones at this price!
Look for a plastic-wrapped tray with a red banner on the plastic stating, "24 cans for £5".
Not sure when/if this deal will end soon, suspecting they are trying to get rid of old stock (sell/use by date on my pack was Dec 2010).