Quite difficult to tell from the piccy. The stuff Tony has is "Lysimachia", I think that the plant we are looking at is a little too upright for that but difficult to tell. "Ranuculus" (Cellandine) should, as has been said, stopped flowering by now. Look for little bulbils at the base of the stems, it would prefer the shade of the nettles to the direct sun I think. A good outside bet would be "Stellaria" (Chickweed) or possibly even some sort of "Campanula". At the moment without closer inspection I would say "Chickweed" as it grows like billyo and likes freshly disturbed ground, if it is it should get little white flowers. Dragging up very old knowledge here!!