Confidence: It's likely to be this, but I can't be certain.
Notes: I have found that in the North-East at least the treatment published in the Plant Crib (1998) and followed in Stace 3 works pretty well. On that basis I would call this plant E.verna, E. glabrescens being much, much hairier and E. majuscula having, amongst other characters, petals which are split only to 1/2 way - these are clearly spiit to a greater depth. But I'm no expert! Just carrying on the discussion really.