Clearing when holding a med offer

Hello,
I have a query about clearing,
If I am holding a Medicine offer from a Uni (lets call it Uni 1), but I want another Uni (lets call it Uni 2) that I didn't initially apply to and it may go to clearing on results day, how would it work through UCAS? Especially with an interview being there a day or 2 after results day! I dont want to risk losing my Med place from Uni 1 by declining it and going into clearing, Would I phone up Uni 2 and then do an interview with them, then if they offer me a place, I could safely decline my previously firmed offer from Uni 1 then accept Uni 2? or would I have decline Uni 1 if I want to do an interview with Uni 2 on results day?
Or is what I'm talking about outright impossible?

Please reply if you know how the clearing system works (especially when an interview is involved/for Medicine)
and please state whether you're 100% sure of your answer or just speculating, etc...
If there's someone specific that needs to be tagged please tag them, im still new on tsr

Thanks for any responses in advance 🙂

[I've moved your post to a new thread as it wasn't relevant to the thread you had posted in.]
Have a read through last year's clearing FAQ:
https://www.thestudentroom.co.uk/showthread.php?t=7505793
What you are proposing is unlikely. Clearing is for those who are not holding an offer or a place. You can phone a uni with clearing places on results day to see if they would consider you, but it is unlikely that they will progress to interview if you are still holding a place elsewhere.

You really can’t do what you want to do, because clearing isn’t designed for people holding an offer so they can shop around.
Yes, you can speak to another uni whilst still placed elsewhere, but they may either refuse to have a clearing conversation with you, or the limited places may simply have gone by the time you’ve had the call, released yourself from your offer and then called back.