The European Commission has followed the lead set by Ofcom last month and introduced rules for harmonising the use of mobile phones in aircraft.

However, the technical and licensing rules govern flights only within EU airspace. Unless neighbouring territories fall into line with the Commission, airlines will not be able to offer the service on flights outside the EU.

Mobile carriers and airlines have been lobbying hard for the Commission to approve in-flight calls as a means to generate extra revenue.

Until recently, aviation authorities worldwide have maintained that mobile phone signals from aircraft to conventional cellular base stations on the ground interfere with aircraft navigation and flight-control systems.

But the development of miniature cellular base stations known as picocells means that an aircraft can be fitted with its own base station and use a satellite link for connecting calls with the cellular network, reducing the likelihood of interference.

Some airlines, such as Air France and Qantas, have already run pilot programmes to enable in-flight calls from passengers' mobiles.

The inherent international nature of flight means EU-wide rules were a necessity, according to the Commission.

Pricing of calls from aircraft is not covered by the EU rules and will be left to operators.

However, the Commission has taken a strong interest in lowering roaming charges among EU member countries, and a bluntly worded statement from EU Telecoms Commissioner Viviane Reding warned operators not to gouge in-flight callers.

"We expect operators to be transparent and innovative in their price offerings," she said. "If consumers receive shock phone bills, the service will not take-off."

Reding also called on airlines to "create the right conditions onboard aircraft to ensure that those who want to use in-flight communication services do not disturb other passengers".

Given the tightly packed layout of most commercial aircraft, this may prove a challenge. Limiting mobile users to data only, i.e. SMS and internet access, has been suggested as a solution.