The government has confirmed plans to put 51% of the country's air traffic control system into private ownership, to generate investment by the private sector.

This has been fiercely opposed by air transport unions who say it would create a "Railtrack of the skies".

But National Air Traffic Services (NATS), a subsidiary of the Civil Aviation Authority, say privatisation will provide much needed capital.

Air traffic controllers are also due to move to better equipped control centre at Swanwick in Hampshire from their current home at West Drayton in Middlesex. But the relocation has been dogged by a series of technical problems and put back by several years.

Dr Gavin Strang, the former transport minister, is opposed to the privatisation of the air traffic control industry.

We have a great record in this country in the area of air traffic control. I believe that when the new centre at Swanwick is up and running that it will confirm our position as the leading country in terms of safety and quality of the air traffic control service.

But the top priority has to be to get the new centre up and running - and not for the management to be diverted from that challenge with all the complexities involved in a privatisation, and this could be a very complex privatisation, quite frankly.

When it comes to air traffic control there is no question that safety is the overriding concern. Anything you do to the arrangement has to be judged against the objective of raising safety standards. And nobody in the British public will believe that privatising air traffic control will raise safety standards. And I think rightly so.

It has been put forward for financial reasons...really you cannot justify privatising air traffic control in order to extract money from aviation and put in to something else.

It's also not just the air safety issue - which is paramount where the ordinary air traveller is concerned - it is also security. If there is a potential incident on a plane - sadly you cannot rule out terrorism these days - then I think it is very important for the security system in this country to be able to take control immediately of air traffic control. I think this is facilitated by retaining it in the public sector rather than privatising it.

Air traffic controllers have been under a lot of pressure but they have stood up well. It's a compliment to them and their managers that we have continued to maintain the highest standards in this country.

Bill Semple is the chief executive of National Air Traffic Services Ltd - a subsidiary of the Civil Aviation Authority. NATS provides most of the air traffic services in the UK.

The government's proposed Public Private Partnership (PPP) for National Air Traffic Services would mean we could secure funding needed to invest in the future of the UK air traffic control systems and keep it one of the safest in the world.

So long as NATS is in the public sector it will always have to compete for funding with spending priorities like hospitals or schools. Yet NATS will need as much as $1bn over the next 10 years to keep pace with annual air traffic increases of around seven per cent..

The PPP would also give management the freedom and clearer responsibility to manage the business more effectively. And it would mean that a company which is already a British success story would be able to exploit its expertise and reputation and expand overseas.

But the bottom line is that safety is our business. We will never cut corners on safety. The latest figures show that the number of risk-bearing proximity incidents involving NATS' controllers are the lowest for many years. And Wednesday's report by the House of Commons Transport Sub-Committee recognises that liberalisation and privatisation around the world have led to improved safety.

As NATS will never compromise on safety, any shortfall in investment could only result in delays caused by air traffic control going up. This is already starting to happen this year in Europe. We in the UK are holding our own at present, but we would like to do better than that. We don't want delays, nor do our airline customers, nor does the travelling public.