Deputy Prime Minister Musalia Mudavadi on Monday took his bid for nomination as ODM's presidential flag bearer to Mombasa County.
Mr Mudavadi, who is also the Local Government minister, said party rules stipulate that there be county nominations.
"The party has to show it is democratic by ensuring that rules are followed to the letter. ODM is not a dictatorship but a democracy," he said.
Speaking at a meeting attended by more than 260 delegates, Mr Mudavadi said the party should devolve to the grassroots.
Work with anyone
"We are not doing this because of pressure. These rules were made by the secretariat, and that is why I am going to different counties to educate members on how the exercise will be carried out," he said.
"I am ready to work with anyone who wins the nomination as long as it is done in line with party policies."
Declaring that ODM was ready for the election, Mr Mudavadi called on President Kibaki and Prime Minister Raila Odinga to announce the date.
ODM national vice chairman Ramadhan Kajembe and organising secretary Hassan Joho supported Mr Mudavadi and urged those interfering with party matters to back off.
"We welcome everybody but those who are trying to disrupt our party should stop," said Mr Kajembe.
Meanwhile, an ODM MP has joined calls for Mr Mudavadi to abandon his bid for the party's presidential ticket.
Mr John Mbadi (Gwassi) said Mr Mudavadi was "misadvised".
The MP, a staunch ally of Mr Odinga, the party leader, said on Monday that Mr Mudavadi was "being used by enemies to break up the party".
The MP said Mr Mudavadi has support "from the likes of Charles Keter (Belgut) and Elijah Lagat (Emgwen)".
The two MPs are staunch supporters of Eldoret North MP William Ruto, who has also expressed his ambition to be Kenya's next president through the United Republican Party.
"You have to be very suspicious when you see a Democrat being supported by Republicans. We need to ask ourselves, why? If we suspect that someone is trying to break up the party, we have to say so," said Mr Mbadi.
The MP said the choice of party flag-bearer should be left to the national delegates conference.
Meanwhile, civic leaders in Busia have castigated ODM MPs who are against Mr Mudavadi's bid.
Led by Camulus Obada and Jack Wambulwa, the leaders said the party should embrace democratic processes.
"We are asking the MPs to respect one another and allow the party delegates to decide between Mudavadi and Mr Odinga," Mr Wambulwa said.
He said that there was no need to call Mudavadi names and associate him with ODM rebels.
They backed Mr Mudavadi's calls for party nominations to be held at the county level.
The civic leaders said it was sad that few individuals were trying to divide the party for selfish gains.
They said that the PM had already made it clear that he will support Mudavadi if he emerges the winner and wondered why a section of MPs are opposed to him.
They asked Mudavadi not to be cowed by people out to break the party.