This sign has been inserted on the grass outside my house without any consultation or prior notice

I arrived here today for the first time since 7 January to fine this sign implanted in the grass outside my house and about three feet from the entrance to my drive and garage. There had been no prior consultation or notice provided to me. The siting is bizarre and inappropriate as is evident from the position on the map - two thirds of the way along the street (rather than at its ingress at the junction with Court Hill Road or near there). Plus it would be difficult to exceed 20 mph on this residential street, which is short, generally has vehicles parked on at least one side of the road and off which KIng's Close goes, which, like this one, is a cul de sac. I would like this unnecessary and unsightly impediment removed. In addition, please inform me (a) whether this was the intended position for this site; (b) under what legislation/powers it has been placed there, whether any consultation ought to have occurred and, if so, what. Thank you in advance for your assistance,