No, they won't change their mind now they've announced it. The best recourse anyone has is if the voucher or gift card was bought with a credit or debit card and then the purchases may be able to claim the value of the voucher through their card issuer. In my direct experience, however, card issuers don't like having to pay out such claims and will do anything they can to put you off. Be persistent and don't take the first answer they give you.

Administration means that things like vouchers are of no value. Major creditors get some of their money back but small claims are wiped out.

It's already been announced that Vouchers are invalid as of today

I feel so sorry for those losing jobs,and off course those losing money

Sadly none.

Is there any likelyhood that the administrators will relent upon invalidating the HMV music vouchers ?

So many people of all ages will have been given these as Christmas gifts and they are now valueless. It is just as embarrassing for the gift giver as the recipient.

Please to everyone, don't take out your anger on any shop staff, remember they have lost their jobs and they had no part in the voucher ( i can only call it) scam.