We should be clear and distinguish deodorants in general from antiperspirants specifically. Aluminum compounds are the only known effective antiperspirants, you can ask for an aluminum-free antiperspirant but you'll get a product that doesn't work very well (if at all). However, there are many options for aluminum-free deodorants that aren't antiperspirants.

I thought it was well known that antiperspirants should be avoided because of the aluminum.

→ http://www.saje.com/ca/peaceful-warrior-4011.html → https://everymanjack.com/body/deodorant.html

I have used these and are not bad. See if you can get these in the UK.

Some big names that I've used. Speed Stick, Tom's.. usually it says "deodorant" on the label but not "anti-perspirant"