Alan Jarvis has been unsuccessful in his appeal against the British Horseracing Authority's decision not to grant him a training licence.
The BHA's licensing committee announced in March that the handler would not be granted a full licence after deciding he was "not a suitable person".
The reasons for the decision were not revealed at the conclusion of the first hearing, although Jarvis was declared bankrupt last year over debts owed to Doncaster Bloodstock Sales Ltd which have still not been settled.
Jarvis, whose training career spans over 40 years, was granted a temporary licence to continue operating from his Buckinghamshire stables pending the result of Tuesday's appeal hearing.
However, the 75-year-old failed in his attempt to overturn the original decision and is said to be "very disappointed" his long spell in the training ranks is now over, with his son Tim now hoping to assume control at Mill Race Stables.
A statement from Jarvis' barrister Roderick Moore said: "Alan is naturally very disappointed that he has not been granted a full licence to train, and that his training career, which has spanned many decades and produced scores of winners and placed horses, will shortly be brought to a close.
"While he accepts of course that he fell into debt to Doncaster Bloodstock Sales Ltd, he regrets that DBS used and then carried out threats of an objection to his licence and bankruptcy as a means of debt recovery.
"Given that he is now 75 years of age, the consequence of this state of affairs is that his retirement from training, and hopefully his replacement by his son Tim, will have been brought forward by a year or two.
"He looks forward to helping and supporting his son Tim, and hopes thereby to enjoy remaining involved in racing, the sport to which he has given the entirety of his working life, but perhaps without some of the stresses and strains of recent years.
"He wishes to thank his family, staff and owners for their unstinting support, as well as all the many others in racing who have pledged their support over the last few difficult months."
Adam Brickell, director of integrity, legal and risk for the BHA said: "The licensing committee's original decision to find Alan Jarvis an unsuitable person to hold a trainer's licence followed an objection from the BHA Executive to the renewal of Mr Jarvis' licence.
"The licensing committee considered a substantial weight of evidence relating to a number of factors relevant to Mr Jarvis' suitability, including examples of Mr Jarvis failing to act with the integrity expected of a licensed individual.
"BHA therefore welcomes the decision of the appeal board to dismiss the appeal lodged by Mr Jarvis."
The full reasons for the BHA's decision will not be published until Wednesday, but the authority confirmed Jarvis has been given another temporary licence until 27 May, with the trainer being allowed to make entries until 19 May.