China Southern Airlines offers quite interesting solution to travellers planning to discover Vietnam during next main tourist season 2014/2015! Open-jaw flights to Hanoi and Ho Chi Minh City are currently available from just Ł387. (no matter if you fly first to Hanoi or Saigon). To reach the cheapest fare available you have to consider departures ex Prague, Amsterdam or possibly from Paris. Your return flight has to be then back to London. Take the opportunity to visit classic tourist place such as Ha Long Bay close to Hanoi. As you would be heading to south you should definitely not miss imperial forbidden city Hue. Going further down you may take some rest at beach side in Nha Trang. We also recommend to visit Da Lat, city completely different to any other you can explore in this country. (also very refreshing if you want to escape hot weather due to its higher altitude).
The cheapest flights to Vietnam are available when departing from Prague. However, as the difference is very low and you would have to accept one more layover, most of you should consider to depart from Amsterdam. As mentioned this tariff allows to fly to Hanoi and Ho Chi Minh City during main tourist season 2014/2015. You can find such a low fare between October 2014 and end of March 2015!
If you can accept a bit longer stop-over in China this is an interesting offer to this South-East Asian country. Please remember that you can get free tourist visa on arrival in China (up to 72 hours). Take the opportunity to visit another city and country on your way to Vietnam..
Apart of cheap flights between Amsterdam and London (for instance one way ticket with Easy Jet is available for just Ł28) you may also consider to use Megabus. Coach tickets with this company is possible to purchase for just Ł1 during their repating promotions!
Booking sample of cheap open-jaw flights to Vietnam (Hanoi, Saigon) during main tourist season 2014/2015 for just Ł394. In this case you would be flying from Prague to Hanoi on 9th of February. Your return flight from Ho Chi Minh City back to London would take place on 23rd of February 2015.