I spent some time wondering what this was and ended up going back to have another look, book and lens in hand. It is greater chickweed, with downward pointing buds and seed capsules, 8-10 stamens, and oval, opposite leaves. Common chickweed and lesser stitchwort have similar flowers but 8 or fewer stamens and long, narrow leaves respectively.
The cold weather has held back the usual showy display of spring flowers but look closely and you can see a new backdrop of ground ivy, which is aromatic when crushed.
Jack-by-the-hedge or garlic mustard is just starting to flower…
Still on a theme of white, with wood sorrel, wavy bittercress (6 stamens, delicious), greater stitchwort and ribwort plantain, with ransoms almost in full bloom
Blues are becoming more prominent, with bluebells, alkanet, slender speedwell and cornsalad recently flowering
Purples include prolific common dog violets, ivy-leaved toadflax, and new flowers of bush vetch