been looking at rs tuning in leeds for a remap,would i need to tell my insurance?

cheers Stu

Yes. Every change over standard should be disclosed.

Yes.

Worst case you don't tell them, have an incident and they pay out for a 3rd party claim then come after you for the cost of doing so while invalidating your cover and leaving you uninsured. That then becomes a criminal matter and the CPS will come after you for driving without insurance. That conviction and even the fact that cover was withdrawn by your insurer has lifelong implications to your premium in future. Again I'll stress that's worst case but you don't knowingly fail to declare anything to your insurer.

Normally if it's minor such as aftermarket alloys you weren't aware of they will demand payment of the additional premium before progressing the claim.