Don't expect a huge "For Sale" banner to sell off NSL. As for evidence, its all there to see. First step was station grading to depress salary levels as a long term goal. Training for Aerodromes OR Area to prevent operational staff mobility back to the area side........you have evidence aplenty that management cross over the area-aerodrome bridge with amazing regularity in both directions....when the sell-off occurs they will be across to the safe side en masse. The current Pensions issue.
Remember the descriptive phrase "One NATS Two Businesses"......hardly competent management to have two complete sets of management running in parallel..........UNLESS!!!!!!!!!!!!
What is the nature of the evidence that you require?