The closure of UK airspace is costing British Airways around £15 million to £20 million a day, the airline said today.

By Peter Woodman, Press Association Air Correspondent

A successful British Airways test flight through parts of the "no-fly zone" around the UK showed that "the current blanket restrictions on airspace are unnecessary", the airline said today.

BA chief executive Willie Walsh joined a flight crew on board a Boeing 747 test flight that set out yesterday evening from Heathrow and went out into the Atlantic before landing safely at Cardiff.

Today, BA said analysis of the flight had revealed "no variations in the aircraft's normal operational performance".

In particular, the aircraft's "black box" flight data recorders showed that all four engines had performed "without fault for the duration of the flight".

The aircraft flew as high as 40,000ft during the two hour 46 minute flight.

Mr Walsh said today: "The analysis we have done so far, alongside that from other airlines' trial flights, provides fresh evidence that the current blanket restrictions on airspace are unnecessary.

"We believe airlines are best positioned to assess all available information and determine what, if any, risk exists to aircraft, crew and passengers."

He went on: "Since airspace was closed on Thursday our assessment is that the risk has been minimal and can be managed by alternative procedures to maintain the highest, safest standards.

"We call on the Government urgently to adopt new policies that would allow us to resume flying.

"Safety is the overriding priority for an airline. We use our expertise in risk assessment across a wide range of safety issues to make decisions on the safe operation of flights every day.

"We believe that we should be allowed to take the same responsibility over safety issues over the recent volcanic eruptions in Iceland."