GT,
Just to clarify, the Lighting Operators are NATS staff, so the final say in L/Op numbers is down to NATS, as long as the coverage was pursuant to the ATS contract with HAL.
Of course, the NATS contract with all the London BAA airfields is coming under great cost pressure from BAA's new owners who've made it very clear, so I hear, that the continual and incremental contract cost increase that the 'old BAA' was happy with is no longer good enough.