Wulfy:
They test you in the language, in your case French and I think it's something along the line that they have a talk with you about your family, friends, hobbies and stuff.
They make you read something like the safety demo in French and I think they make sure you are fit to assist in a medical emergency, means you know words like heart, pain, cramp, blood...so you can pretty much talk about signs and symptoms...
Not sure if there's anything written.
I've only got this second hand anyway as I've never had a language test.
You might want to consider Edinburgh and after six month you can apply for a base transfer to London!