Missing "no left turn" sign

A new pedestrian crossing was recently added to this junction (yellow "x") and the traffic lights changed from a regular green light to straight ahead and right turn arrows. However there's no explicit "no left turn" sign, and because of the sequence of these lights the traffic shown in the photo has a green light at the same time as the pedestrians on that crossing. I've seen a number of times that vehicles will turn left here, although fortunately there hasn't been anyone crossing at the time. A sign here would make the junction safe for pedestrians, who understandably may not think to look behind them before crossing on a green light.