From LASORS 2008 Section E Page 10
IR Conversion Requirements
These arrangements will provide a route to JAR-FCL IR(H) qualification for the following holders of a current and valid* IR issued in accordance with ICAO Annex 1:
ICAO IR (H) holder to JAR-FCL IR (H)
ICAO IR (A) holder to JAR-FCL IR (H)
JAR-FCL IR (A) holder to JAR-FCL IR (H)
* The holder of an ICAO IR(H)/(A) or JAR-IR(A) that is not current and valid will be required to attend an approved FTO and complete a modular course of IR(H) flying training.
So, yes, you do have to be current unless:
If during the course the Head of Training is prepared to state in writing that completion of the FULL course is unwarranted and recommends a reduction, PLD will give the recommendation consideration.