Instructors and IR/IMC ratings
 

Help! In the last year I have converted onto the A320, so I can't use my IR on light a/c as I used to when flying the B737 (yes I know its all changed with JAR as well. As I intend to continue to instruct in the Uk, do I need to do an IR or IMC rating again, in order to have an instrument qualification on light aircraft?

As you hold a CPL/ATPL you have automatic, lifetime IMC Rating privileges so, unless you want to fly in regulated airspace, you can do all the things you need for instructing. If you want a SEP or MEP IR then I'm afraid it's the dreaded revalidation check ride with a CRE/IRR.

The previous comments are correct provided you retain your UK ATPL. If you convert to a JAR-FCL ATPL you don't have the inbuilt priviledge and would have to take either an IR or IMC test on SPA.