Use your mirrors and give a left-turn signal well before you turn left. Do not overtake just before you turn left and watch out for traffic coming up on your left before you make the turn, especially if driving a large vehicle. Cyclists, motorcyclists and other road users in particular may be hidden from your view.
CAN THE GREEN CAR GO BEFORE THE CYCLIST HAS PASSED THE JUNCTION?
Do not overtake just before you turn left. HC rule: 182.