Zimbabwe (search) opposition leader Morgan Tsvangirai (search) was acquitted on treason charges Friday, a surprise end to a yearlong trial that his party had said was orchestrated by the government of President Robert Mugabe (search).

Hundreds of Tsvangirai's supporters danced for joy outside the courthouse when the verdict was announced. Inside, Tsvangirai's wife Susan hugged and kissed him and defense attorney George Bizos stood with tears of joy streaming down his face.

"The acquittal is a huge blow to the forces of tyranny," said Gibson Sibanda, the vice president of Tsvangirai's Movement for Democratic Change (search) party.

Tsvangirai had been charged with treason two weeks before he contested presidential polls that Mugabe narrowly won in March 2002. He and his part had described the trial as a a way to sideline a main government opponent.

He still faces a separate charge of advocating Mugabe's violent ouster.

The charges stemmed from state accusations Tsvangirai plotted to kill President Robert Mugabe with the help of Canada-based political consultant Ari Ben Menashe. Tsvangirai could have faced the death penalty.

Judge Paddington Garwe, who took an hour and twenty minutes to read his judgment, said the state failed to prove that Tsvangirai ever asked Ben Menashe to help assassinate Mugabe.

Garwe also said it was clear that Ben Menashe wanted to entrap Tsvangirai. He also said Ben Menashe was not a reliable witness, had accepted money from the state and that his testimony was not supported by any independent credible witness.

The ruling came as a surprise because of the widespread expectation that Mugabe would be able to impose his will on a court system that has been criticized as political and corrupt. On Wednesday, Tsvangirai had said his fate would be decided by outside political forces, not the judge.

Since his victory, Mugabe has moved to tighten his grip on power, packing the courts with judges loyal to his party, closing the country's independent press and silencing dissent with a security law that restricts freedom of speech and association.

At the same time, he has used police and other security forces to harass opponents and journalists and deployed state-controlled militias of youths and purported veterans of Zimbabwe's war against white rule to violently suppress dissent.

The highly charged case centered on a secretly recorded videotape of a meeting between Tsvangirai and Ben Menashe on Dec. 4, 2001 in which the opposition leader allegedly sought help to kill Mugabe.

Tsvangirai said he mentioned Mugabe's "elimination" on the grainy and barely audible 4 1/2 hour tape referring only to Mugabe's possible defeat in the upcoming presidential polls and any subsequent change of government.

Tsvangirai denied the charges, insisting they were a government ploy to frame him and discredit the opposition ahead of the presidential poll.

During the trial, state prosecutors withdrew allegations Tsvangirai asked Ben Menashe's help to "murder" or "assassinate" Mugabe.

Tsvangirai's defense team argued Ben Menashe was already working for the Zimbabwe Central Intelligence Organization in a bid to ensnare the opposition leader when the Montreal meeting took place.

Bizos, Tsvangirai's lawyer, said his client sought Ben Menashe's help in good faith to raise support and funds for the opposition in the United States and Canada ahead of the polls.