Noel Edmonds has accused Lloyds Banking Group of "foot dragging" over compensation payouts to fraud victims, and also demanded a meeting with its chairman.
The former Deal or No Deal host last week launched a £50 million compensation claim against the lender, claiming he has suffered "deep distress and public humiliation" caused by fraud at the hands of former HBOS Reading staff.
Lawyers for the TV star wrote to Lloyds' boss Antonio Horta-Osorio demanding payment for "immense economic loss" and "distress and inconvenience" following the HBOS fraud scandal.
However, in another strongly worded letter, this time to Lloyds' chairman Lord Blackwell, Mr Edmonds rages against the bank's compensation process.
"Since you have appointed only one individual tasked with assessing what will be complex and substantial claims from at least 100 fraud victims it is difficult to see how your assurance that compensation will be paid 'within weeks' can be adhered to when the necessary infrastructure has not been put in place."
He added that "no urgency whatsoever" has been shown by the bank to meet compensation claims, claiming instead that Lloyds has been "foot dragging".
He also criticises Mr Horta-Osorio for refusing to meet with him, and urges Lord Blackwell to take up the baton.
The letter continues. "May I suggest therefore that you agree to such a meeting in the next few days so that you can then direct the future actions of your bank with a full understanding of the human cost of its wrongdoing."
A group of corrupt HBOS financiers were jailed earlier this year for carrying out a £245 million loans scam that destroyed several businesses, before they squandered the profits on high-end prostitutes and luxury holidays.
Mr Edmonds claims that one convicted ex-HBOS employee, Mark Dobson, helped destroy his former business Unique Group.
Lloyds said last month that it would begin making compensation offers to HBOS fraud victims in May from a £100 million pot, with payments expected to begin in June.
The bank added that if a review determined that the level of compensation requires it to increase the provision then "we will absolutely do so".
Mr Edmonds's solicitor Jonathan Coad, from Keystone Law, said: "Lloyds has known for at least four years both that its employees have acted unlawfully towards many of their customers, and that their victims have suffered severely as a consequence.
"Far too late both its chairman and chief executive have pledged that compensation will be paid promptly, at a time when payments should have been well under way. But the bank continues to drag its feet. It is disgraceful that to date no compensation has been paid by the bank to victims of its fraud."
In a statement, Lloyds Banking Group said: "We have confirmed to the customer concerned that they have been included in the review, which is being overseen by Professor Russel Griggs as independent reviewer.
"The review will assess any compensation due and will provide an opportunity for customers to input directly on any aspects of their interactions with the HBOS Impaired Assets office in Reading.
"We remain on track to begin making the first compensation offers before the end of May and anticipate making compensation offers by the end of June to all customers who have confirmed their participation in the review."