Two Foreign Currency firms I have used a few times which have a reasonable spread are Hargreaves Lansdown for transfers over £10,000 and Smart Currency Exchange for transfers over £5,000. Both firms don't charge a transfer fee above these amounts and have better rates than the scamming banks.
When you ring you will be asked to complete ID checks as with opening a bank but they are quite easy, also try asking to improve the rate they offer you. (If offered 1.1620 Euros you may get 1.1650 Euros just for asking.
There are many more firms about who offer this service but these are the only 2 I have used so far.