I saw a huge (for the UK) wasp with a red/orange back which I have never seen before which I have been unable to identify. It was ca. 100% larger than the everyday wasp you see around middle England.
What type of wasp is it?
That's not a wasp, it's a type of hover fly. According to the Nature Spot website it's called a Volucella zonaria:
This is a hornet mimic and is one of our largest and most spectacular hoverflies which can be recognised by its yellow and black banded abdomen. It is chestnut on tergite 2 and also on the scutellum and much of the thorasic dorsum. The only similar species is V. inanis which lacks the chestnut areas and which has sternite 2 yellow rather than black.