New 14 day quarantine from 8th June advice pls

[justme36]

I am a British citizen travelling to Heathrow on 17th June. I then need to catch another flight to Bulgaria 2 hours later from the same terminal but it's not a connecting flight. These are 2 separate tickets. I have to pass border control to collect my bags and then go to catch another flight. But if I pass border control it is as if I have entered the country. So I am considered a landside transit passenger. Will I be quarantined?

I read all government advice online and there is no such information anywhere. It is not clear!

Please advise

Indeed Ginfordinner! I feel so relieved

If the same airline, make sure you have your parents address all over your baggage and request to check it to the final destination on check in at Brazil.
I have done this before on 2 separate tickets.

I don't want to worry you, but the US have just suspended travel from Brazil for foreigners.

Yes I saw that too. Hopefully no other countries do. My flight leaves on 16th June

If you have no check-in luggage you can certainly go to flight connections directly, so long as you have your boarding pass (and most airlines will let you get this directly on your phone).
I've done this - I stupidly went to the wrong gate and missed my flight, but was able to book another on my phone and go straight to the new gate without back out.
If you need to check in luggage, and your Bulgarian flight is with the same airline or the same airline group as your London flight, you would probably be able to check luggage straight through to Bulgaria - best to ring the airline and confirm first though.
If you can't do this, I'd consider trying to move the Bulgaria flight to later, as 2 hours is very short to land, do passport control, possibly health checks by June 16 and check-in again. In Heathrow, you must be at security at least 45 minutes before your flight departs.