Shaun Brady, who was involved in the infamous Barbecue Brawl, urged members of the train drivers' union Aslef to insist that he resumed his post as general secretary.
That causes massive problems for Aslef whose members elected a new leader in the wake of Mr Brady's dismissal. It also causes embarrassment to the union movement as a whole, which is urging the Government to enforce reinstatement for those who win unfair dismissal cases.
The Central London Employment Tribunal yesterday found that Mr Brady, a Blairite, had been hounded out of a top job by a political campaign mounted by the union's left-dominated executive. The tribunal adjourned to January 17 to consider compensation and Mr Brady's call for reinstatement.
The former Aslef general secretary emerged from the tribunal saying he was "absolutely elated'' by the decision. "I leave this court today an innocent man," he said. "My actions have been vindicated. My whole life has been disrupted by this.
"The members of my union now have every right to demand I take up the position to which I was democratically elected.''
Mr Brady, who now runs a pub in Southampton, was dismissed after internal hearings found that he had refused to co-operate with an inquiry into the union's finances. His involvement in the fight with union president Martin Samways on May 20 last year was not the cause of his departure.
The chairman of the tribunal, Valerie Cook, said the union had not followed its own rules in getting rid of Mr Brady and had not properly investigated the allegations made against him.
She said the former South West Trains driver had faced "a blatant hostility'' from the executive. Their opposition was manifest the moment he was elected in preference to the left winger and incumbent Mick Rix.
She pointed out that Mr Brady had been a train driver with no managerial experience and had found that the union's staff were refusing to work with him.
Keith Norman, who was elected general secretary after Mr Brady's departure, said he was "devastated'' by the tribunal's findings.
"I was hoping the tribunal would base their decision on fact rather than fiction,'' he said. The union would now be taking the case to the Employment Appeals Tribunal.
Mr Norman said he had been democratically elected to the post of general secretary in June.
"I'm not going anywhere, I've done nothing wrong,'' he said. He said that any question of Mr Brady's reinstatement was a matter for the executive.
He denied there had been a campaign against Mr Brady. "At no time did the executive engage in a conspiracy," he said. "It acted with propriety.''
Asked if the tribunal's decision and the barbecue brawl had brought the union into disrepute, he said: "There's no doubt we have been on the wrong end of the media.''
Last year a report drawn up by Matthias Kelly, a former chairman of the Bar Council, found that Mr Brady had treated his organisation's staff "aggressively and insensitively''.
The document said that "an atmosphere of paranoia gripped the union'' after Mr Brady took office and a "smear campaign'' was conducted against Mr Rix.
Key players in union drama
* SHAUN BRADY
Blairite former South West Trains driver elected leader of Aslef in 2003 and dismissed in 2004 for his refusal to co-operate with an internal inquiry. Involved in "Barbecue Brawl'' with union president Martin Samways.
* KEITH NORMAN
Member of the left- dominated executive which sacked Mr Brady. Elected to the top post in June after Mr Brady was sacked. Although he received left-wing backing, supporters hope that his avuncular public image will be a unifying force.
* MICK RIX
A left-winger and leading light in Arthur Scargill's Socialist Labour Party who lost to Mr Brady. Like his predecessor, Lew Adams, whom he defeated, he underestimated the power of the protest vote within the union.
* MARTIN SAMWAYS
Traditional trade unionist who resigned as president of the union last year after admitting that his involvement in the infamous "Barbeque Brawl" with Mr Brady was an error of judgement. Has said he will no longer stand for union office.