Performers at Russia's Bolshoi Theatre made a last-minute plea for leniency yesterday for a dancer accused of ordering an acid attack on its artistic director, praising his "wonderful human qualities" and saying he was incapable of the act.

A judge is due to pronounce a verdict today in the month-long trial of former soloist Pavel Dmitrichenko that has shone a spotlight on bitter rivalries behind the scenes.

State prosecutors have asked for a nine-year prison term but he could still be jailed for up to 12 years if convicted over an attack that nearly blinded the Bolshoi ballet's artistic director, Sergei Filin.

The month-long trial of Dmitrichenko and two alleged accomplices has tainted the reputation of one of Russia's most prominent cultural symbols.

"In the open trial, the public has heard absolutely no evidence confirming his guilt," dozens of performers and other staff at the Bolshoi said in an open letter published on the website of the daily Izvestia newspaper, which was signed by about 150 people.