Sir Stelios Haji-Ioannou, the ebullient founder of EasyJet, used to be on such good terms with Mark Dixon, the man behind the rise and fall and rise again of office group Regus, that he recommended him for membership of the Monaco Yacht Club.

How the winds have changed. The pair, both residents of the exclusive principality, have locked horns over what Sir Stelios claims are “dirty tricks” designed to stymie his entry to the serviced office industry, the latest market the serial entrepreneur is trying to crack.