Use a VW approved 502.00 oil. Popular choices are Mobil 1 0w40, or Castrol Syntec or Valvoline 5w40. Not sure if both of these are available in the UK. I believe these may be available for you (Elf Excellium LXD, or Motul E-Tech 8100) in the 5W40 weight.

Here is VW's list for North America.

Here is a great resource for oil questions in general.