Postal Order/Bankers draft for paying in Euros (UK banks)

Does anyone have an idea what is the best/easiest/cheapest way to pay the Naturalisation for Irish Citizenship fees? (From a UK bank)

The form asks for payment with a bankers draft or a postal order.

I'm just off the phone with Santander and each bankers draft would be £10, I'm not sure if there are better ways to make the payment without fees but can't find much information about payment in a different currency. (Though at the end of the day, £10 isn't too much but would rather avoid it if possible)

Hi
Have you checked about the postal order? though it is bit cheaper then bank drafts.

Thanks, I got this sorted yesterday.

The post office couldn't do it for me as they couldn't do it in Euros.

I ended up going with the Santander option for £10, it didn't take too long, thought it was the best option as my other bank (Halifax) said it would take a few weeks to arrive and I needed to get it sorted quickly.