On behalf of over 3,000 air traffic controllers, engineers and specialists, Prospect National Secretary Garry Graham said: "We welcome the fact that the government has recognised that NATS is a crucial part of the UK aviation infrastructure and of key strategic importance.
"The government has clearly listened to the representations made by stakeholders for safety and service delivery to remain paramount, and for the UK to continue to have an authoritative voice in Europe, particularly during the development of the Single European Sky initiative."
However he warned that while the government decision provides a welcome degree of stability, "all eyes will now turn to the Airline Group – and their intentions."
The Airline Group currently owns a 42% stake in NATS and retains significant powers under the Strategic Partnership Agreement.
"The need for stability and a commitment to safety and service delivery should be at the heart of any decision that they make," said Graham. "They purchased their stake because they had a vested and visceral interest in safety and service delivery. We are concerned that their position is now focused on short-term commercial gain."