Here is his statement in full.

The UK aviation security regime is one of the most developed in the world.

It was further tightened in the aftermath of the 11 September attacks in the United States, and is kept under permanent review.

Earlier this year that process of review led the government to decide that the existing package of measures for in-flight security should be reinforced, and deterrence increased, by the development of a capability to place covert, specially trained armed police officers aboard UK civil aircraft, should that be warranted.

That threat remains a real one, but this new capability has not been developed and is not being announced now in response to any new or specific intelligence.

This further security measure joins others the government has taken to increase security both on the ground at airports and in flight since the attacks in the USA.

We have stepped up the search regimes for staff, passengers and their hand and hold baggage, vehicles, cargo and catering, with a particular emphasis on flights going to key destinations such as the USA; added to the range of articles not able to be taken aboard aircraft; and extended the National Aviation Security Programme to smaller aircraft and aerodromes.

Additional funding has been made available for airport policing.

We have also accepted in principle all of the recommendations of Sir John Wheeler's recent review of airport security, which will in particular enhance the co-ordination of the security effort across different departments and agencies.

On in-flight security, we are moving faster than the international community at large to ensure UK aircraft are fitted with intrusion-resistant flight deck doors, and last month we acted to ensure that flight deck doors on foreign aircraft are kept locked, as they have been on UK aircraft since very soon after the US attacks.

We have also placed strict limits on those able to be on the flight deck of UK aircraft. The Government will continue to work with the UK airline industry on sustainable measure for responding to the terrorist threat.