Disgraced Chinese leader Bo Xilai has agreed to plead guilty at a trial, likely to be held within weeks, in an apparent bid to earn a more lenient sentence.

But it is not clear if he would plead guilty to all or only some of the charges of accepting bribes, corruption and abuse of power.

Bo's downfall is the country's most divisive political scandal since the 1976 downfall of the Gang of Four at the end of the Cultural Revolution.

President Xi Jinping is keen for Bo's trial to go smoothly as he pushes major economic reforms ahead of a closed-door party plenum in September or October where he will need full support from the party.

A source close to the family, who also spoke on condition of anonymity, said Bo will plead guilty, but should not be held accountable for crimes committed by immediate family members.

The abuse of power charge is believed to be linked to the murder of British businessman Neil Heywood by Bo's wife, Gu Kailai, when Bo was the party chief in sprawling Chongqing city.

Gu was convicted of the murder and Bo's police chief, Wang Lijun, was jailed for trying to cover up the crime.