CORD leader Raila Odinga has told all political aspirants on ODM tickets to avoid violence.
The ODM leader said accelerated political activities in Opposition strongholds were affecting the battle to remove Jubilee from power.
Raila said it was wrong to engage in high levels of aggression at a time when the legitimately elected leaders are still in office.
"This bickering has to stop. If you are eyeing a particular seat, that is fine. But we still have people occupying those seats. Once the seats are declared vacant, then we can all go to the people and ask for their votes," said Raila.
He was speaking in Nyatindo in Kasipul constituency, Homa Bay County, on Monday.
Members of the Odinga family were visiting Raila's sister, Wenwa Akinyi.
Last month, chaos erupted at an ODM rally in Homa Bay as supporters of Governor Cyprian Awiti and Kasipul-Kabondo MP Oyugi Magwanga clashed.
While Mr Awiti's supporters chanted slogans in support of his re-election, those of Mr Magwanga, who has declared his interest in the governor's seat, said he must be voted out next year.
And when push came to shove, a shouting match ensued before it turned physical.
The debacle at the Homa Bay stadium was further compounded by a fist-fight between Homa Bay Town MP Peter Kaluma and aspirant Washington Ogaga.
Raila also took the opportunity to up his calls for the people of Nyanza to register as voters, saying they have the numbers to fell Jubilee in next year's polls.
"As I have always said, we have enough adult population with identification cards but who are yet to register as voters. Those are the people we need to win the coming elections," said Raila.
In the recent weeks, the CORD leader has been leading calls for the Nyanza people to register as voters, a strategy that is seen as aimed at galvanising the entire region ahead of next year's polls.
"How I will look for votes in other regions is my assignment. Leave that to me. All I want from you is to register in large numbers," he said.