Bo's political career was stopped short last year by a scandal which saw wife Gu Kailai convicted of poisoning a British businessman.
Bo is now on trial charged with corruption, taking bribes and abuse of power, the last of which involves allegations Bo challenged the authority of the ruling Communist Party.
Despite Bo's defence, a guilty verdict is a foregone conclusion as China's courts are controlled by the Communist Party.
Since the trial began on Thursday in Jinan, Bo has repeatedly denied wrongdoing and has called his wife's testimony against him the ravings of a mad woman.
On Sunday, Bo rebutted earlier testimony from his former police chief Wang Lijun. Wang said he had told Bo that his wife Gu had murdered British businessman Neil Heywood.
"He is continuing to lie obviously, and what he is saying is totally unreliable, it is full of deception, he's just mouthing off," Bo told the court. "He has a vile character, spreading rumours here and muddying the waters."
Wang has also been convicted and jailed over Mr Heywood's murder.