Unless you have a non-UK JAA FI(A) rating, which has no restriction.
A brand new JAA instructor coming to the UK from overseas to work are not restricted in the same way as a UK issued FI(A) and can sign off solos and supervise a UK FI(A) (R) who has x00 hours of instructing but has only managed to get 24 solo sign offs.
It raises an interesting question. Who has it right? The UK with it's imposition of a restriction on new FI's or all other JAA member states with no such restriction.
Head over the parapet, stand by for incoming!!!