Daniel Kretinsky on the future of Royal Mail and Sainsbury’s

In just over a week, Daniel Kretinsky will break a golden rule. The billionaire Czech co-owner of Sparta Prague football club has never set foot in arch-rival Slavia Prague’s stadium, even for a national game or a music concert. “I had a huge mental/moral reservation,” he says. But on June 7 he will be there with his son. West Ham are playing Fiorentina in the Europa Conference League final — and Kretinsky happens to own 27 per cent of West Ham. What draws an energy tycoon from eastern Europe to an east London club? “I simply love the colours and the jersey,” he says, laughing.

There is also a longstanding Czech connection. The former national goalkeeper Ludek Miklosko played for West Ham between 1990 and