Air traffic control company Nats insisted it faced no political pressure to ease the restrictions.
"We don't feel we have been under pressure from the Government," said spokesman Alex Bristol.
"Where the pressure has come has been to better understand the safety implications."
- we overreacted on poor information and have been forced to reassess
Transport Secretary Lord Adonis said there was now a "better" understanding of the effects of volcanic ash on aircraft.
"The CAA have been working around the clock with the aircraft manufacturing industry, the airlines and the research community to better understand how different concentrations of ash affect aircraft engines," he said.
"As a result, the CAA has now established a wider area in which it is safe to fly, consistent with the framework agreed by the EU transport ministers."
- We are climbing down from out untenable position because we now know that nanny doesn't know best
Willie Walsh, chief executive of British Airways, has said "lessons can be learned" from the handling of the event.
He added: "I don't believe it was necessary to impose a blanket ban on all UK airspace last Thursday.
"My personal belief is that we could have safely continued operating for a period of time."
- the airlines are looking for someone to blame
Strangely as predicted - despite the new eruptions.
DB-I am well aware of the premature embrittlement of the turbine blades caused by excessive temperatures - we were warned of this last week.
Iron - I suggest you read the NASA report on the inadvertant entry to ash cloud about exactly how the damage occurred - the holes
were blocked in the turbine blades because the ash is different to sand. Now I know you know more about engines than me but excessive creep would mean the blades would impinge on the casing which would certainly be visible with a borescope, wouldn't it?