Q. I want to visit family and friends in Sydney from 27 December until 16 January. I don't want a stopover. All the flights from Heathrow seem to cost at least £1,200 return. Can I find flights for less anywhere? Shari Rendle, London
A. Over Christmas and New Year, too many people are chasing too few airline seats. For most of the year the many competing airlines struggle to extract more than £1,000 for a round trip in economy on the London-Sydney route. But when demand outstrips supply, the carriers understandably make hay while the sun shines (in Sydney, if not London).
On your dates, the best deals I've found are on China Southern via Guangzhou or Air India via Delhi. Each is around £1,200, and each requires a long wait in the transit lounge. Faster trips on "premium" airlines are around £1,500.
Your return date is just fine – by mid-January the spike in demand has eroded. The problem is the departure date. You are not the only Brit who wants to spend Christmas at home but then escape to the southern hemisphere to spend the New Year watching the fireworks in Sydney harbour. But if you can move your departure date a day earlier you'll get a faster flight for the same £1,200 fare. China Eastern has availability via Shanghai: you leave Heathrow at 9pm on Boxing Day and arrive at 10am on 28 December.