By Richard Chidwick
The six day shutdown of Britain's airports has led to calls for official inquiries by opposition politicians.
While flights are now permitted again, the fallout of the crisis has prompted MPs and flight company officials to call for an probe into what they say was a lack of response.
Theresa Villiers, Conservative shadow secretary of state for transport said: "We saw real concerns with the government's lack of action in terms of taking action to rescue people while the skies were closed.
"It took them far too long to get their act together on that.
"We need to ask some searching questions about the judgments made by the government."
But Liberal Democrat transport secretary Norman Baker criticised the Tories' response as being electioneering.
He said: "It's pretty reprehensible for the Conservatives to be almost gleeful about the chaos that there has been." and he called for an inquiry after the election.
"The government is responsible for many things in this country but a volcano going off in Iceland is not one of them.
"There are so many questions to be asked, I think the transport select committee perhaps after the election will have a full inquiry into this to see why it is the Met Office advice was so different to Euro-control's."
But the shut-down has also been attacked by airlines, who lost hundreds of thousands in revenue, every day they couldn't fly.
Willie Walsh, British Airwaves chief executive said: "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."
Michael O'Leary, Ryanair's chief executive, also attacked the grounding of flights, saying: "We do have to question whether an eruption over Iceland poses a safety risk to flights operating over Spain, Italy and France, several thousand miles away."
A Virgin Atlantic spokesman also voiced concern about the ban. He said: "We think that more reliable scientific data should have been gathered so we could have had a clearer picture of whether there were areas where it would have been possible to fly aircraft safely."
Gordon Brown defended the government's decision which left 150,000 Britons stranded overseas: "What matters now is people can get back as quickly as possible.
"We've got the best metereological office in Europe, we provide information not just for Britain but for the rest of Europe. They have to look at what was happening at the volcano, how much ash was in the environment. Some of it was falling to the ground so they had to send up test flights with the airlines... a lot of work had to be done.
"The first thing people want to be sure of is if they fly in an airplane they want it to be safe."