This might actually be possible if @shumble is using the prepaid card.
You can bank transfer to the prepaid card from a bank account and I think Monzo use a Barclays bank account as a holding account for the prepaid card (which technically should have a UK IBAN attached).
I will not try to explain how to do this as it is very at your own risk, but it should be simple to work out the IBAN. I will put below the details how to do a UK bank transfer to a Monzo prepaid card.