From an answer I gave in an earlier thread about role plays at Virgin:
"Normally, you are all put in a room together, and you get given a story. It's usually something along the lines of your boat has sunk and you have to pick which objects are the most important to survive, or the world is about to end and you have to choose from a list which people you would save. You get given a few minutes to make your own rankings, then you all discuss it as a group and try to reach a consensus together. It's a good way of seeing which people are too quiet or timid to get their voice heard, and which people are too dominant. Communication and team working skills are vital so thats what you really need to demonstrate."
Don't worry about it too much, with these things it's usually the more relaxed you are the better you will do! Virgin like their staff to be warm and outgoing, and relaxed, so if you can show all that you're already half the way there. And I know it's hard to be relaxed at a recruitment event (especially when normally you have to do a few written tests first just to get through to the group exercise), but the recruitment team are pretty great at putting you at ease. If it's a Manchester position I'm assuming you're assessment is at Crewe? It's a really nice venue and it also helps keep you relaxed!
Also, bear in mind the fact that hundreds will have applied for this job and only a few get invited to an assessment day, so thats another big step you've already taken.
Good luck
