A veteran of the industry who worked at peer Green Flag, Mr Mackenzie was a protege of legendary asset stripper James Hanson early in his career, whom he said taught him to “work hard and play hard”.
He said his experience with the famed businessman had helped give him a “hands-on operating background”, which made him ideal at getting to grips with the AA’s troubles.
His departure will see senior independent director John Leach take the chairman’s role, while non-executive director Simon Breakwell, who has held senior positions with Expedia and Uber in the UK, becomes acting chief executive. Martin Clarke will remain as chief financial officer.
Along with news of Mr Mackenzie’s departure, the AA issued a pre-close update saying performance in the first half had been “robust” with personal membership edging up to 3.327m despite rising insurance premium tax.