China's decision to try fallen politician Bo Xilai's wife for murder underscores Communist leaders' determination to draw a line under a scandal that has engulfed the party ahead of a power handover, analysts say.

China announced Thursday that Bo's wife Gu Kailai and an aide to the couple had been charged with poisoning British businessman Neil Heywood, who was found dead in a hotel room in the southwestern city of Chongqing last November.

It was the latest development in a sensational case that has brought down one of the country's most high-profile political leaders and exposed deep divisions in the ruling Communist party ahead of a once-in-a-decade leadership handover.

Bo, the son of a revered Communist revolutionary, won national fame with a draconian crackdown on criminal elements in Chongqing and a "red revival" campaign marked by the mass singing of old Maoist-era songs.

The rapid unravelling of his fortunes earlier this year exposed a harsh factional reaction against the charismatic Chongqing party secretary, who had ambitions to join the elite nine-member group that effectively rules China.

Analysts said Thursday's announcement indicated that senior Communist chiefs, keen to settle the Bo affair before a new generation takes the reins of power later this year, had reached broad agreement on his fate.

"There won't be any more surprises. They are trying to shift the focus to Gu Kailai, so it is quite possible that Bo Xilai will not be treated harshly," said Willy Lam, a China expert at the Chinese University of Hong Kong.

"This could be out of necessity for party unity, for the sake of harmony before the party Congress."

Several academics said the announcement indicated that Bo, who is being investigated by the party for "violating party discipline" -- usually code for corruption -- would be spared criminal charges.

This was likely the result of a deal between competing factions within the party ahead of the upcoming Congress, when China's most senior officials will relinquish their party positions to a new generation of leaders, they said.

"With these cases being dealt with at this time, I expect there to be smooth sailing to the 18th Party Congress," said Boston University international relations expert Joseph Fewsmith.

"There may be some bargaining to go, but most of it has been done."

Joseph Cheng, political analyst with Hong Kong City University, said the Party's determination to present a united front before the handover meant Gu's trial would "demonstrate that the case has nothing to do with Bo Xilai".

"I think the political considerations are more important to the authorities than ensuring a fair trial," he added.

Thursday's announcement on state news agency Xinhua said there was "irrefutable and substantial" evidence that Gu had poisoned Heywood after he threatened her son following a row over "economic interests".

The British businessman reportedly had commercial dealings with Bo and his wife going back several years.

China's state-run media have positioned Bo's downfall and Gu's trial as evidence that no leader is above punishment for misdeeds, in a country where official corruption remains a major source of public discontent.

An editorial in both the English and Chinese-language editions of the state-run Global Times daily on Friday said the trial would test "whether the principle that everybody is equal before the law truly stands".

Beijing is also under pressure from London to ensure that justice is done following the murder of a British national.

But analysts said the wording of the Xinhua announcement indicated that Gu was certain to be found guilty. If convicted of murder she faces the death penalty, although this is often commuted in the case of high-profile defendants.

It is not yet clear when the trial, to be held in the eastern city of Hefei, will take place, but experts, including City University's Cheng, said it would likely be next month.

"The leadership wants to have the issue settled publicly in response to domestic and internal pressure before the Congress," he said.