The decision is the latest embarrassment to rock Ucatt following recent election scandals and the fiasco of its ongoing attempts to elect a new general secretary.
Dooley was dismissed from his role as a Ucatt official in February following claims that he did not have the right paperwork filled-in when signing-up new members.
He was still standing as a potential candidate to replace former general secretary Alan Ritchie who was removed from office following voting irregularities.
But Ucatt council members decided last week to ban Dooley from the election race.
Croydon Employment Tribunal ruled yesterday that Dooley was unfairly dismissed by the union but he was 50% responsible for his removal from office.
The Enquirer understands that Dooley was claiming a £200,000 payout meaning the maximum he can now receive is £100,000 at a future awards hearing.
Dooley said: “This is a sad time for my union.
“First the leadership are guilty of holding an illegal election, then their appeal of that decision fails now they have been found to have sacked a union official unfairly.
“The biggest criticism is of the procedures the union used to dismiss me, a union in my view should know how to conduct fair procedures.
“After all we are always on at employers who do not follow fair procedures when they want to get rid of a troublesome employee and here we are unable to follow a fair disciplinary procedure.
“It’s a disgrace and an embarrassment but I dare say no one will be to blame yet again”
It is understood Dooley will use any payout to seek a court injunction against the leadership election after he was barred from running despite receiving widespread support.
He said: “I now have to contend with the election being run without my name on the ballot paper until I can take steps to change that position”