Hmm, I'll ring up in a moment to see if they still want to do it... god I am going to sh*t myself live on air.
Hey - realistically, what's the worst that can happen?
They don't ask you back?
If it was me:
1. I have no idea what you look like, but get their make-up people to give you a quick once over to reduce studio glare, trickle sweat, stuff like that.
2. Don't bring up the England thing unless they ask. And don't treat it seriously (no-one really takes it seriously). If it sounds like you have a crusade, you'll sound like a geek.
3. Count a heartbeat before answering any direct questions.