With opposite pinnately compound leaves the first thought is ash. A black terminal bud is also an ash characteristic, but I'm not 100% on matching the leaflets, in some pictures it looks like Fraxinus excelsior and in others not so much. Perhaps one of our European members is familiar with it since Electricsheep is in the UK, @JRsbugs@bonitin
I don't think it is the Common Ash either, the leave surface on Electricsheep's plant looks having relief, (not flat like on Ash), and the leaf petioles look hardly existing..: https://www.google.be/search?q...