You can prune it back by a third to a half, but not till late next Spring, or in early summer.

You can prune it quite hard, but it's best done in the spring. Advice is to clip it - but also that it will regrow from hard pruning, so good luck if you decide to do it.

Snap, Bamboo! :-)

Well yes and no, Spritz - you're quite right in that regular clipping over is much better than a major hacking back when its got too big, not to mention less risky in terms of the plant surviving major surgery.

Useful answer. I've got an overgrown pottosporum in one of my customers gardens and I've wondered about a severe pruning. It seems this will be OK if done in spring.