It may be slightly different, I don't know, but last year there was a kerfuffle when Swazi-registered Gazelle helicopters were effectively grounded by the CAA. G-reg ex-mil Gazelles (not the pukka civil ones) are restricted to Permits, and this was a way round this.
Is there a parallel, and if so once a precedent's been set, may it be done again ?
I think it would be heavy handed, but then again . . .