If the payment will be going to an organisation that accepts debit cards then, as TTT suggests, that's the way to go. Otherwise consider using PayPal Xoom to transfer the funds:
https://www.paypal.com/uk/webapps/mpp/send-money-abroad
Many thanks to you all. I've just looked on my bank account and it seems I can do it from there if I get IBAN and BIC numbers. Though it looks like Chris' idea is £16 cheaper.
The easiest and cheapest way is to use Wise (was Transferwise)
I transfer money to Turkey on occasions to pay bills on our property.
Last week I sent just £10 to my Turkish account and it was there next day at negligable cost. Last year I sent £1000 and uit was there next day. DO NOT use your bank, they will sting you!