On 11 November 2019, three prime ministers took to the stage at a five-star hotel in London. The premiers – from St Lucia, Albania and Montenegro – were speaking at a conference put on by Henley & Partners, a firm that acts as matchmaker between the super-rich and countries selling citizenship.

Allen Chastanet, from the former British colony St Lucia, reassured the audience that they wouldn’t actually have to live on the Caribbean island, just invest $100,000 and buy a house there. The real prize on offer was a ‘golden passport’ that bestows visa-free travel to 145 countries, including the UK, members of the EU Schengen area, Hong Kong and Singapore.