Cause célèbre Twitter defendant Paul Chambers has won an appeal against an almost farcical conviction for a tweeted ‘joke’ that authorities took literally as a threat to blow up a British airport.

"Crap! Robin Hood airport is closed. You've got a week and a bit to get your shit together otherwise I'm blowing the airport sky high!,” Chambers, 28 tweeted to 600 followers in January 2010 after bad weather closed Robin Hood airport near Doncaster as he was trying to travel to Northern Ireland.

Unfortunately, the light-hearted tweet was noticed by a member of staff at the airport who informed the police, leading to his arrest at his place of work for authoring a communication of a “menacing nature.” 

Originally found guilty of threatening the airport in May 2010, Chambers, 28, was eventually fined £385 with around £2,600 in costs. He later lost his job and claimed that he had become unemployable as a result of the publicity.

After losing one appeal against conviction, on Friday Chief Justice Lord Judge, Mr Justice Owen and Mr Justice Griffith Williams took a different view.

"We have concluded that, on an objective assessment, the decision of the crown court that this 'tweet' constituted or included a message of a menacing character was not open to it. On this basis, the appeal against conviction must be allowed."

In short, the message was not menacing at all and should have been taken in context by the airport, the police, and the Crown Prosecution Service (CPS), which now faces huge criticism for spending thousands of pounds on public money pursuing the case.

As well as being congratulated by several well-known public figures including actor Stephen Fry, Chambers was also backed by his constituency MP, Louise Mensch, who was in court to hear the judgment. Many supporters had backed the case on free speech grounds.

"The CPS owe the whole country an enormous apology for having wasted public money and put him through two and a half years of serious stress for what was a joke,” she said.

"When parliament returns we will be asking searching questions about why freedom of speech was trashed. There was nothing menacing about this message. It was completely obvious."

Chambers solicitor, David Allen Green, added:

"This shameful prosecution should never have been brought. For two and a half years the CPS have adopted a ridiculous position. There are very serious questions for the director of public prosecutions to answer in this case."