BEIJING (AP) — Chinese lawmakers stripped disgraced politician Bo Xilai of his last official position today, formally expelling him from the country’s top legislature and setting the stage for criminal proceedings against the once-rising political star.

Though largely a formality since Bo was purged from the Communist Party late last month, his expulsion from the congress removes his immunity from prosecution. That sets the stage for a criminal case involving accusations of corruption and other wrongdoing, including interfering in the investigation into the murder of a British businessman. Bo’s wife and a household aide were convicted for the murder last month.

Party leaders are keen to resolve the country’s messiest political scandal in decades as they prepare for next month’s once-in-adecade transition of power. They are handing over to the next generation of leaders, who will be tasked with shoring up public support in the face of widespread disgust over official graft and influence peddling.

They may even want to push through a trial before the opening of the party congress on Nov. 8, though some experts say there may not be enough time.

Preparations will involve leaders reaching a consensus on how harshly to punish Bo, which of his associates to include in the trial and ensuring the accused remains compliant in the courtroom, said Ding Xueliang, an expert on the Chinese leadership at Hong Kong University of Science and Technology.

“It’s really a very muddy situation,” he said.

As the most powerful official in the southwestern mega-city of Chongqing, Bo had been considered a candidate for a seat on the party’s all-powerful Politburo Standing Committee, and his toppling exposed sharp infighting in the party’s uppermost ranks.

The National People’s Congress Standing Committee said it approved a decision to remove Bo as a deputy, but offered no details.

Bo’s downfall has been spectacular: His wife, Gu Kailai, was convicted of murdering British businessman Neil Heywood, and Bo’s former right-hand man was accused of taking bribes, abusing power and trying to defect to the United States, among other crimes.

Even before that, Bo had angered many in Beijing with his populist style that defied the authoritarian party’s demands that those seeking higher office merely follow orders from Beijing and maintain a low-key image. Bo’s initiatives included a sweeping crackdown on organized crime and a campaign to revive Mao-era songs and culture that reminded many of the excesses of the 1966-76 Cultural Revolution.