Former shareholders of Bradford & Bingley should not get any compensation after the troubled business was split and sold, an independent valuer said.
The bank was split into "good" and "bad" parts in the aftermath of the banking crisis, with the better half sold to Santander.
Now independent valuer Peter Clokey has recommended that the Treasury offer no compensation to shareholders.
The decision would affect 935,000 investors.
B&B's shares closed at 20p in the final day of trading before the nationalisation and break-up of the group. The "bad" part of the bank stayed with the government.
The B&B Shareholders Action Group plans to appeal against the decision by Mr Clokey, of PricewaterhouseCoopers. The group had previously said that any valuation below 55p a share would be "tantamount to theft".
"Peter Clokey has today delivered a damning verdict on the rights of UK shareholders. This is a very sad day, not just for B&B shareholders but UK shareholders in general," said the group's spokesman Richard Jennings.
In the two days before administration, some £173m was taken out of B&B.
Mr Clokey said that, without nationalisation, the bank would have fallen into administration, leaving nothing for shareholders.