It's all in LASORS, mate of mine got caught with this last year. CAA refused to issue a type rating as he was a PPL/IR and had not attended a 'High Performance Aircraft Course'. Any type of aircraft in LASORS with HPA next to it requires you to do the HPA course unless you have an ATPL or Frozen ATPL. I think the only people in the UK to offer the course are in Bournemouth (possibly ETA)