A man who held a group of people hostage at gunpoint in an Edmonton Workers' Compensation Board office has lost his appeal.

Patrick Clayton had asked the Alberta Court of Appeal to rescind his guilty pleas or, failing that, reduce his 11-year prison sentence.

Clayton, who was armed with a hunting rifle and 100 rounds of ammunition, herded nine people into a conference room in the downtown building on Oct. 21, 2009, before surrendering peacefully 10 hours later.

He pleaded guilty to hostage-taking, pointing a firearm and possession of a weapon for a dangerous purpose.

Representing himself, Clayton argued that the trial judge had threatened him, that the Crown had promised a lighter sentence and that the hostage-taking was justified because of how the board treated him over a work-related knee injury.

The Appeal Court ruled the evidence did not support any of Clayton's claims and that the sentence was justified.