President Uhuru Kenyatta marshalled Jubilee supporters before the party's nominations today.
He warned that violence would be severely punished.
The President said leaders who incited their followers to violence would be disqualified on the spot, while election officials found engaging in any form of irregularity would face the law.
"Any acts of violence will lead to disqualification and misconduct may be subject to penalties under the law. The culture of hooliganism during the electoral process must not and will not be allowed to gain currency and acceptance," he told journalists at a news conference in State House, Nairobi.
The Party's strongholds in Central and Rift Valley regions, which will go to the primaries today, have attracted strong entrants for governor and MP seats.
As the party starts its greatest test yet, to filter its many aspirants and remain intact, the President said every contender has an equal chance of getting the ticket. He denied that the party had favourite aspirants.
"There are no candidates favoured by the Jubilee Party leadership and I will work with the people that wananchi elect and together, we shall present to the nation our shared vision and agenda," said the President.
The Jubilee Party heads into the primaries today, joining other political parties that have been conducting their nominations amid chaos and reports of irregularities.
The Orange Democratic Party, for instance, cancelled results in Busia and parts of Narok following reports of irregularities.
It has also delayed announcing results in Taita-Taveta after some polling stations failed to receive election materials on time.
The Chama Cha Mashinani too, postponed its primaries in two constituencies in Bomet because of lack of materials.
Jubilee has extended its nominations period, opting to conduct them over three days as opposed to one day as planned.
Party officials on Wednesday said the change was because of the need to ease pressure on those charged with logistics.
Some aspirants have criticised the extension, claiming it was meant to favour certain candidates by giving them more time to campaign.
On Thursday, the President said the nomination dates should be agreeable to all aspirants.
He said the government would not condone violence from any party but added that he wanted to set a good example to the rest of the country by conducting free and fair nominations.
"Let us show everyone how party primaries can and should be conducted -- in a calm, professional and civilised manner," he said.
The party is expected to hold nominations in 45 counties today, Monday and Tuesday.
It briefed aspirants on the electoral code on Tuesday.
But the President says the ball is in the court of the 60,000 polling officials hired by the party.
"Party election officials must perform their duties with integrity and whoever will fall short of that will face the law.
"They must ensure that it is the voice of the people to be heard, not Uhuru or any other person.
"They have done a good job so far, but they should not spoil it at the eleventh hour because of certain influence," said President Kenyatta.
The President also denied claims that he endorsed Mr Peter Kenneth to run for governor of Nairobi, ahead of primaries in the city on Monday.
In a preparatory briefing to journalists, President Kenyatta clarified that he had only asked residents of Mr Kenneth's home county to pray for their son.
"We just happened to be at the same funeral and I told the people of Murang'a that this is your son who wants to be governor of Nairobi and I asked them to pray for their son to be successful," he said