At perennial favourites oi polloi http://www.oipolloi.com/oipolloi/shop/sale.php reductions increased this week on labels such as MA Strum, YMC, Nom de Guerre and Oliver Spencer.
Flannels http://www.flannelsfashion.com/c45717/Men-Clearance.html have a few Woolrich, Stone Island and C.P. Company jackets at up to 50% off plus the Paul Smith London shirts are always worth a look.
Over at Tessuti http://www.tessuti.co.uk/ in Chester theres 50% reductions on MA Strum, Stone Island and C.P. Company jackets plus Gant and Paul Smith shirts.
Also check my-wardrobe http://www.my-wardrobe.com/menswear/sale for sales prices up to 75% off including YMC, Stone Island and Paul Smith.
And finally the 80s Casuals deadstock page http://www.80scasuals.co.uk/shop7.html contains a few t-shirts and sweatshirts at up to 50% off the retail price in store. This page is here all year round so it's worth re-visiting every now and again for a bargain.