Welcome to FT!

There is indeed a luggage storage area in Galleries Arrivals, to the left of the reception desks. There is a member of staff on hand who will take your boarding pass details and give you a number tag for your belongings.

For security reasons, you cannot leave your luggage if you are not in the lounge (although you can leave the lounge and re-enter as many times as you like before the 2pm closing time if you take your luggage).

There is no need to go down to the Underground station - there is a desk and self-service machines in the Arrivals area on the same level when you come out of Customs (Galleries Arrivals is one level up).