Updated

A man who was convicted and fined for tweeting that he planned to blow up an airport says he will take his case to Britain's High Court.

Lawyers for Paul Chambers said Monday that leading human rights lawyer Ben Emmerson will lead the legal challenge to Chambers' conviction.

Chambers was arrested in January after he posted a message on Twitter saying he would blow Robin Hood Airport "sky high" if his flight was delayed.

Chambers insisted it was a joke. But a judge found him guilty of sending a menacing message over a public telecommunications network.

This month another judge rejected Chambers' appeal.

The verdict caused a wave of outrage on Twitter, with thousands of supporters retweeting Chambers' message.