Quite a few of these have popped up in one of my beds, adjacent to the Cornish hedge, but there's nowt on the hedge that looks remotely like it.
Google lens offers Epilobium (willowherb) or Polygonum persicaria (Redshanks).
Doubts as these are MUCH bigger than the willowherbs that appear on and around the hedge ( E. parviflorum, Hoary willowherb and another I haven't been able to ID, as yet) , and I haven't seen redshanks since I've been here.
My first thought was Impatiens, but, again, not seen any locally.
There are LOTS if foxglove seedlings, scarlet pimpernel and I have scattered some hollyhock seed, but they are not any of those.