Roselyn Akombe, a senior member of Kenya's electoral commission (IEBC), has fled to the US amid death threats ahead of next week's presidential election re-run.
"Commissioners and other IEBC personnel were facing intimidation by political actors and protesters," Ms. Akombe said.
She added that she received anonymous death threats, and had been under pressure to resign.
She overall did not "feel safe enough to be able to go home" in the foreseeable future".
Ms. Akombe recalled the murder of the election commission's IT head, Chris Msando, before the August poll.
"You'll be suicidal to think that nothing will happen to you."
"I have never felt the kind of fear that I felt in my own country," she said.
Ms. Akombe said was distressed over the decision to leave the IEBC because "the commission in its current state can surely not guarantee a credible election".
She said the IEBC was under political "siege" and was unable to reach consensus or take any decisions.
IEBC chairman, Wafula Chebukati, said he regretted Ms. Akombe's decision to quit and warned Kenya's political leaders not to "interfere with the process".
The opposition leader, Raila Odinga pulled out of the re-run after the Supreme Court annulled the result of the original 8 August poll after finding irregularities and illegalities when current President Uhuru Kenyatta was declared the winner.
However, the IEBC has said that Mr. Odinga's name will remain on the ballot paper.
They argued that he had not filled in a legally required form informing of his decision to pull out.
Mr. Odinga insists though that filling out the form is not required, and has been organizing mass protests to demand electoral reforms before the re-run is to take place.
"There is a very high likelihood that the mistakes that some of the presiding officers made during the last election will be repeated," Ms. Akobe said.
She also questioned the commission's leadership, saying Mr. Chebukati was ineffective.
Mr. Chebukati says he has given credence to this view and has given the politicians the "yellow card".
"I've made several attempts to make critical changes but all my motions have been defeated by a majority of the commissioners."
"Under such conditions, it's difficult to guarantee a free, fair and credible election," he said.
President Kenyatta has yet to comment on Ms. Akombe's resignation or Mr. Chebukati's criticisms.
He instead called on the nation to an "extended period of prayer and reconciliation" on the weekend.
"We walk towards the declared date of the 26th of October both as a God-fearing leadership and government," he said in a televised speech.