Declan Ganley
Rank 2017
Not many businessmen have the gumption to sue foreign governments but Ganley's tussle with the Mexican state certainly does not lack drama. As his telecoms operation prepared to submit a bid to build a $7bn mobile network in Mexico, Ganley claims document boxes were snatched by a mystery thief on a motorbike. He still submitted the bid within the deadline, but the Mexican government would not consider his tender, saying it lacked vital paperwork. Ganley has since threatened the state with legal action. Irishman Ganley was born in Watford but returned to live in the republic at the age of 13. He runs Galway-based Rivada Networks, which in 2015 secured $50m of funding. Before that it was valued at £450m, though there are reports it could be worth more than £3.6bn. Ganley, 48, is best known in Ireland for leading the 2008 campaign against the EU's Lisbon treaty. We cautiously keep him at £400m.