Before worrying about the regulatory issues, where exactly does the demand come from? If all LHR-PER-SYD does is cannibalize LHR-SIN-SYD, what sense does that make to BA. Even if BA were authorized to sell PER-SYD to fill the vacant seats from the PER O&D traffic, how much of a market is there for a one-off inconveniently-timed PER-SYD flight on BA?