Nasa presidential candidate Raila Odinga claims the National Intelligence Service (NIS) is party to a plot by Jubilee Party to rig the August 8 General Election.
Mr Odinga on Tuesday also accused President Uhuru Kenyatta’s party of dragging the Kenya Defence Forces (KDF) into the elections.
Military officers, he said, are being trained to man the polls as officials.
This, he said, was a repeat of what happened in the run-up to the disputed 2007 presidential polls that resulted in violence.
More than 1,133 Kenyans lost their lives in the 2007-08 chaos and another 650,000 lost their homes and property.
According to the Nasa leader, NIS held two meetings in Naivasha "to come up with a plan to help Jubilee retain power at all costs."
The meetings, he said, were held at Lake Naivasha Lodge and the Great Rift Valley Lodge after the High Court ruled that presidential election results announced at the constituency level are final.
"Jubilee appears to be putting all hopes on the old centralised tallying at the Bomas of Kenya that enabled them to doctor and change results,” Mr Odinga said at his Capitol Hill office.
“It is now turning to using intelligence officers to influence the August elections.”
Mr Odinga, who was accompanied by his chief campaigner and Nasa co-principal Musalia Mudavadi, said the agenda of the Naivasha meeting was being executed at the Embakasi Barracks.
At the barracks, he said, there is ongoing training of Kenya Defence Forces on crowd control.
Military officers, Administration Police officers, county commanders and regional coordinators are also being trained "for unspecified roles", he said.
"These trainings under way at the Embakasi Barracks have every semblance with what was done in the same venue in the lead-up to the 2007 General Election in which the APs were later dispersed as election officials and poll agents for Party of National Unity (Mwai Kibaki's then party),” Mr Odinga said
Besides the training, Mr Odinga said "recruitment of 120 military officers from each barrack and unit for unspecified special operations" was also under way.
More than 100 soldiers have already been deployed to Kakamega, he claimed.
"We want to appeal to our military to remain faithful to the traditions of this country and their call of duty and refuse to be dragged into politics," Mr Odinga said.
He went on: "We are challenging the national government and the leadership of the security organs to explain why a select group of military officers would be involved in training civilians like county commanders and regional coordinators."
But in a rejoinder, Kakamega County Commissioner Kang’ethe Thuku dismissed Mr Odinga’s claims that more than 100 military officers had been deployed to the region to facilitate the rigging of polls.
Mr Thuku said the allegations were untrue and the opposition chief should have crossed-checked the information given to him before going public about the matter.
He challenged Mr Odinga to provide proof of the allegations and stop causing unnecessary panic by making unfounded claims.
“Last week, the military were in Kakamega for the recruitment exercise at Bukhungu Stadium and sub-counties in the region and left immediately after they had completed their mission,” said Mr Thuku.
The administrator invited the media to visit his office and investigate Mr Odinga's claims.
He said the government had set up an army base in Mt Elgon sub-county to address insecurity in the region.
“There is nothing like a military camp in Kakamega. I’m shocked by the allegations and Mr Odinga should get his facts right before rushing to make such allegations in the media,” said Mr Thuku.