don't know about Bristol, but I can't see why you shouldn't be allowed to.
providing you buy it in the airport after security (which i guess is what you intend) I don't know of any rules which will stop you.
Unless the airline has any special restrictions.

There's no such thing as Duty Free when travelling within the EU - It's Duty Paid
Duty Free applies when travelling outside of the EU.
I'm quite puzzled why you'd want to buy alcohol in the UK, when it's cheaper in Spain.
Sanji

Quite right Sanji - I was getting confused between duty free and tax free

My ignorance has been corrected

Definitely cheaper to buy it when you get there

alizda wrote:

Quite right Sanji - I was getting confused between duty free and tax free

My ignorance has been corrected

I didn't mean that to come over as though I was correcting you, not at all,

Sanji x

Double apology Sanji - I didn't take it that way sorry if it came over that way

all is good x