Googled "cow parsley". Looks similar but I have your problem also, fast spreading with blue flowers? Much smaller than the parsley. Just have to keep up with the pulling out. Anyone got the species, name and permanent remedy?
Hayling, if you have a different weed start another thread with a photo.
Thanks Hayling, I think it may be cow parsley, I think weeding is the only answer as I garden without chemicals. Never mind it will burn off the Easter Eggs!
I'm not 100% sure that it's cow parsley but is certainly in the Apiaceae (umbellifer) family. They are all quite pretty and as long as you cut the flower spike off before the seeds form, you can leave and enjoy them. Lot's of folk now grow cow parsley on purpose.