AA has said it is "astonished" over news that ousted chairman Bob Mackenzie is pushing for an employment tribunal hearing after being fired over gross misconduct last summer.
The breakdown recovery and car insurance firm may now be forced to defend its decision to sack Mr Mackenzie - a move that was formally announced in August.
AA said in a statement: "We are astonished that Mr Mackenzie is taking this to an employment tribunal.
"We stand by our decision to dismiss him for gross misconduct following his sustained and violent assault on another employee of the AA, and will robustly defend any action."
Reports have linked his dismissal to an attempted spin-off of the AA's insurance arm, which led to a physical altercation between Mr Mackenzie and insurance chief Michael Lloyd, as well as an earlier altercation in a public place with someone not thought to be an employee of the company.
AA has since called on Mr Mackenzie to pay back more than £1.2 million, accounting for annual bonuses stretching from 2016 to 2017.
According to the company's annual report, the former chairman was paid bonuses worth £707,000 in 2016 and £514,000 in 2017.
The firm also embarked on a top-level shake-up, having announced in September it had appointed Simon Breakwell as permanent chief executive and John Leach as chairman.
AA's last set of financial results showed pre-tax profits rising 67% to £80 million in the six months to July 31, while operating profit climbed 35% to £178 million.
Its performance was aided by a 13% increase in new members, bringing total membership to 3.32 million.
The company's shares were trading higher by 0.5% or 0.9p at 165.35 on Monday afternoon.