The ruling is likely to leave the Duke of Sussex with a large bill to pay the U.K. government’s legal fees — in addition to his own lawyers’ costs.
It wasn’t immediately clear if he would try to appeal to the U.K. Supreme Court.
The ruling upheld a High Court judge’s decision last year that found a “bespoke” plan for the Duke of Sussex’s security wasn’t unlawful, irrational or unjustified.