Hi Chris,
The question asks how many staff do you have in the Lab- so unless your TPs assist with lab functions, I suppose response would be same as previous year ( that's what I submitted anyway- and have never counted the TP role as there is minimal impact on lab in their absence). This would be consistent with the UKTLC questions on lab staffing too.
Be interesting to know how others answer this too.
bw
Rashmi