### Clue: Ecologically conscious folk on move – or those in 5 queues! (10)
### Answer: TRAVELLERS 
 ### Explanation: Definition: Ecologically conscious folk on move,those in 5 queues
  Double defn: 2nd: Those in queues at Heathrow Airport(answer to 5down).  I think, though I may be wrong, the "ecologically conscious" addition is to imply that land transportation is more environment-friendly than air.