Without going into the ins and outs of the Duke and Duchess of Sussex’s withdrawal from royal life, still less the merits of the Duchess’s privacy case against the Mail on Sunday, a claim made by her lawyers this morning cannot be allowed to pass without comment. They claim: ‘This contribution of public funds towards crowd security was far outweighed by the tourism revenue of over £1 billion that was generated from the royal wedding of the Duke and Duchess of Sussex which went directly into the public purse.’

Should we really be thankful to the Duke of Duchess of Sussex for stuffing the UK’s coffers as a result of tourists flocking here for the pair’s wedding or being inspired to come here after watching the event on TV? It is pretty hard to square that claim with figures published by the Office for National Statistics (ONS) on tourism to Britain in 2018, the year of the wedding. Far from the wedding boosting tourist numbers, they fell by 3 per cent compared with 2017. There was not even a positive effect on tourists from the US, the Duchess’s home country – tourist numbers were flat. Worse, the amount of money spent by overseas visitors in Britain in 2018 fell to £22.9 billion, a whacking 7 per cent fall compared with 2017. Far from gaining £1 billion in tourist revenues in the wedding year, the country lost £1.7 billion.

Obviously, the royal wedding isn’t the only influence on tourism. The strength of the pound has the most obvious effect on whether tourists decide to visit Britain and how much money they spend while they are here. The pound was relatively strong at the beginning of 2018, although it fell back through the spring and summer. During the main tourist season, in high summer, the pound was at pretty much the same level it had been in the middle of 2017.

Perhaps we should be asking, therefore: did the Duke and Duchess’s wedding actually cost the country tourist revenue? Were people put off by the sight of the royal couple or unimpressed by the backdrop of Windsor? Did they mistakenly assume that Britain would be more crowded as a result of the royal wedding and decide to put off visits to Britain until another time?

I don’t know the answers to those questions, but I feel pretty confident to declare that Harry and Meghan’s claim to have boosted the tourist economy by £1 billion is fantasy.