Irishman,
I was sent a flyer email today from Cathay Pacific, stating a round trip fare of 499 GBP from London to 13 cities in China via Hong Kong, check it out, ... and see if it covers the period your intending to fly back to China.
To the other Brits here, this may be very useful to you too, especially if your lady lives in any one of the cities covered.....
David....