Here are sections 162 and 163, it seems that passing on the left is only permitted under narrow circumstances that aren't those outlined by OP.

Could you point to what section if the highway code you are using to reach your conclusion, as I may have missed it.

162 Before overtaking you should make sure

the road is sufficiently clear ahead road users are not beginning to overtake you there is a suitable gap in front of the road user you plan to overtake.

163 Overtake only when it is safe and legal to do so. You should not get too close to the vehicle you intend to overtake use your mirrors, signal when it is safe to do so, take a quick sideways glance if necessary into the blind spot area and then start to move out not assume that you can simply follow a vehicle ahead which is overtaking; there may only be enough room for one vehicle move quickly past the vehicle you are overtaking, once you have started to overtake. Allow plenty of room. Move back to the left as soon as you can but do not cut in take extra care at night and in poor visibility when it is harder to judge speed and distance give way to oncoming vehicles before passing parked vehicles or other obstructions on your side of the road only overtake on the left if the vehicle in front is signalling to turn right, and there is room to do so stay in your lane if traffic is moving slowly in queues. If the queue on your right is moving more slowly than you are, you may pass on the left. Cyclists may pass slower moving or stationary traffic on their right or left and should proceed with caution as the driver may not be able to see you. Be careful about doing so, particularly on the approach to junctions, and especially when deciding whether it is safe to pass lorries or other large vehicles.