Later this morning the Lord Chief Justice will be handing down judgment for the High Court appeal of the "Twitter Joke Trial". 

This case is about whether a tweet constitutes a "communication of a menacing character" in circumstances where the tweet was self-evidently non-serious and caused no alarm or menace at the time.

In January 2010, an exasperated Paul Chambers suddenly saw news that his local airport was closed, thereby meaning he would not be able to travel to Northern Ireland to see a woman he had met through Twitter.  He tweeted to his 600 or so followers:

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!!

This was not sent to the airport.  Paul did not use the airport's Twitter address.  The tweet was clearly not meant to be credible: the use of hyperbolic language, the two swear words, and the excessive punctuation all point to the tweet being in effect a joke.  Even the ultimatum was absurd - the period given was a vague "week and a bit".  The plain meaning of the tweet was not that Paul wanted the airport to close or in any way menaced; this was a communication of someone who dearly wanted the airport to stay open.

However, some days later the tweet was found by an airport employee in an internet search.  He referred it to the airport security manager, who graded it "non-credible".  He in turn, because of process, passed it to airport security police.  They did nothing but referred it to South Yorkshire police.

And then, one fine day, and without having done anything wrong, Paul Chambers was arrested at his workplace by anti-terrorism police and marched in handcuffs to a police van in front of his colleagues.

After a day of interviews the police themselves realise the tweet was a joke intended for Paul's followers and decide not to charge for the "bomb hoax" offence for which he was arrested.  However, the police consult the Crown Prosecution Service.  The CPS decide to prosecute Paul under section 127(1) of the Communications Act 2003 for sending by means of a "public electronic communications network" a message "of a menacing character".  This offence was previously limited to telephony and dates back to the 1930s; but parliament - without debate - had widened it in 2003 to cover all internet communications.  Paul appears to have been one of the first prosecuted in respect of a communication sent over the internet.

Paul is then convicted in May 2010 by Doncaster Magistrates' Court and ordered to pay a fine and costs totaling £1000.  This conviction was upheld in November 2010 by Doncaster Crown Court by Judge Jacqueline Davis and two lay magistrates.  She ruled:

We are satisfied, on the evidence, that the message in question is menacing in its content and obviously so. It is difficult to imagine anything more clear. [...]

It is, in our judgment, menacing per se.

Paul was ordered to pay a further £1000 in costs.

Paul appealed to the High Court.  In February 2012, a two-judge court failed to agree, and a further appeal was ordered to take place before a three-judge court.  This hearing took place on 22 June 2012 [2] before the Lord Chief Justice (who is also the head of the criminal justice system) and two other experienced criminal appeal judges.  

The appeal judgment is likely to deal with four matters: was Paul's tweet at the time it was found by the search engine still a message sent by means of a "public electronic communications network"; was the tweet as a matter of fact (or "actus reus") of a menacing character; was the tweet sent with sufficient intention that a criminal act be committed (the "mens reus"); and whether overall there was a violation of Paul's right to free expression under Article 10 of the European Convention on Human Rights.

The High Court has a wide jurisdiction: it can uphold the conviction; it can reduce (or increase) the sentence; it can discharge the conviction (which means that technically the offence was committed but Paul no longer has a criminal record); it can remit the case back for a re-trial; or it can grant the appeal outright and order an acquittal.

In the event Paul loses today the next step would be to apply to the Supreme Court for a further appeal on a matter of general public importance.

So today will be Paul's ninth day in court in a case which has now lasted two-and-a-half years.  

The decision is expected at 9.45 am.

David Allen Green is legal correspondent of the New Statesman and solicitor for Paul Chambers in this appeal.  He has been given permission to tweet the result from the High Court at @davidallengreen [3].  

There is a round-up of links on the last hearing at his Jack of Kent blog [4].