And just for redress, Electron is far more common in the UK than pre paid mastercard and FR carry far more from the UK than EIRE.
Electron is not widely available and aside from Halifax every other major bank has abandoned it and replaced it with a debit card.
As for prepaid Mastercard
Compare prepaid cards | Apply for a prepaid card ? moneysupermarket.com
This kinda gives an idea as to availability.