A delegation from Prospect, the union representing 3,500 staff in NATS, sought assurances from Alistair Darling MP that the government will move quickly to stabilise the organisation's precarious finances, and enable it to focus on safe and effective air traffic management.

The union called on the government, as NATS' major shareholder, to provide an immediate cash injection using part of the £765m it received from the sale of the organisation.

Without it, said Prospect aviation officer David Luxton, NATS' ambitious but essential investment plans are directly under threat. 

NATS has confirmed that over 60 per cent of its planned capital expenditure over the next five years is essential for sustaining safety, capacity and service continuity at current levels. 

But already the planned new Scottish air traffic control centre at Prestwick, essential to ensure NATS' ability to safely manage increasing air traffic demands, has been delayed. 

"This would not be a 'lame-duck' rescue but a strategic investment to kick-start external funding from banks and other institutions in essential infrastructure programmes," said Luxton.

"Unless there is an end to the current financial instability it is inevitable that safety will be compromised. That is not scare-mongering - it is the experience of the controllers and engineers Prospect represents."