Further Investigation reveals that over the last 3 years the royal mail has added to it's airsure service:

You can send mail by Airsure® to 30 destinations in the following three geographic postal zones:

Europe: Andorra, Austria, Azores, Balearic Islands, Belgium, Canary Islands, Corsica, Denmark, Faroe Islands, Finland, France, Germany, Iceland, Liechtenstein, Luxembourg, Madeira, Monaco, Netherlands, Portugal, Republic of Ireland, Spain, Sweden and Switzerland.

World Zones: Brazil, Canada, Hong Kong, Malaysia, Singapore, New Zealand and USA
So I'll add the new countries to the list. It's interesting to see that Italy still has not made it to the list. When I was running a shop which eventually sent out items to 48 countries at 20 items a day, Italy lost more packages than any other country with the USA and Australia coming second and third, where the packets were either delyaed massively or damaged in transit. With the USA in particular, it happened very suddenly as if new regulations came into force and was about the time of all the new patriot laws.