There are only 3-4 places for GBP withdrawals. With Coinsbank and Coinfloor there is also Bitwala
https://www.bitwala.com/transfers/ You will receive the transfer up to 3 business days (They usually send it the same day) with a 0.5% fee. There is a verification needed and the company is efficient with their service
Thanks for that. Unfortunately with Bitwala the 0.5% fee is for Euros, GPB is 2.10% (min. £6) according to their website.
Coinsbank seems to be SEPA (which is what I want to avoid) or a card, which has an upfront cost. I'll check Coinfloor out later, as their website doesn't seem to be playing ball at the moment.