Could this be the end of Aldi's beloved budget 'knock-offs'? M&S's legal battle with Aldi over its £4.99 Cuthbert the Caterpillar cake could see more popular items in line for the chop, say retail experts (but can YOU tell the real from cheeky copies?) Lower-cost alternatives could now be under threat, after Marks & Spencer started legal action against Aldi M&S claim that its rival's Cuthbert the Caterpillar cake infringes its trademark on Colin the Caterpillar Experts say M&S is unlikely to win because it would have to prove consumers were 'sufficiently confused' But they say an M&S victory would be a 'can of worms, because it won't end, it will be product after product'