Starting from tomorrow until next Tuesday (19th).
£2.89 for 240 bags is a great deal anyway, but there may be a possibility of getting these for just £2. The 'normal' price for the 240 is £5.78 'ish (just checked Asda and Sainsburys). I bought these on Monday at Tesco, marked as a price cut from £5.78 to £4, which I though was OK. If the link I have put up is working correctly, you will see the offer starting tomorrow says "Half Price, was £4, now £2.89". If the shelf label says the same thing, I'd be visiting Customer Services after being charged £2.89 at the till, claiming that half of £4 is not £2.89. They might just be forced in selling them for £2, and possibly less if they still have to honour 'Double the Difference'