Just returned from my local Tesco and found there are a number of wines (there may be more in larger stores) that are drastically reduced. They don't appear to have the larger shelf tickets that regular offers have, but the shelf edge labels are yellow.
Blossom Hill Merlot £2.49
Hardy's Turning Leaf Zinfandel £3.24
Tesco's Californian Reserve Merlot £2.49
Goiya Reds - 2 varieties £2.49
There may be more in the whites section, but I'm a red only man!
Fill yer boots!