It is no surprise that Yanis Varoufakis, the former finance minister of Greece, turns up to our interview without a tie. The 56-year-old famously arrived at Downing Street in 2015 for a meeting with the then Chancellor of the Exchequer, George Osborne, with his shirt untucked.

More surprising is that the left wing economist, who led negotiations with creditors during the 2015 Greek government-debt crisis, is wearing a suit jacket.