This may be one of those hard to get tesco deals or it may be widespread i dunno but i guess we will find out.
28 pack of the above tablets are being sold for 3.75 but at the moment all packs in my store are 100% extra free so 56 for 3.75 bringing it well below the 'magic' 10p per load.
This may be a discontinued pack size as there were also packs of 14 for 3.50 and packs of 56 for £13. Label is standard white one so may be easy to miss.
If you have these instore its worth stocking up just incase its limited.