Just to give you all a head up - there are some cracking double open jaw flights to Beijing for just £161 over on Holiday Pirates. These go from Lithuania to Beijing and to Stockholm - so not the UK so you will need to account for getting from the UK to Lithuania and back from Stockholm, but even so this has to be a great price and I'd be tempted to do a short city break pre/post China - but I know alot of people don't share my enthusiasm for open jaw flights ;-)
It is flying with Ukraine Airlines though and I know this may put people off. Flights bookable at Budget Air - some screen shots on HP of dates.
May and June dates.