I'm not 100% sure what the procedure is across the pond, but State-side we would have already received a "squawk" code from Clearance Delivery while we were sitting at the gate.

Also, I'm unsure of the procedure over there for being told to join a radial, but that's not how you would hear it here. When I get to a real computer, I'll give you a proper rewrite if someone doesn't beat me to it.