Wiper leader Kalonzo Musyoka insists Deputy President William Ruto was careful to have him arrested and prosecuted to taking oath along with Raila Odinga.
Last month, Raila took oath as people's president in Kalonzo's absence, with the latter giving numerous excuses.
But at Athi River on Tuesday, Kalonzo said Ruto, who is expected to run in 2022, had plotted to have him arrested and prosecuted.
"Ruto was careful to have me arrested and prosecuted in a bid to block my 2022 ambitions. I had tangible information that is why I didn't participate in the oath.
"He knows well Raila will not run and his main target was me. The oath did not abide by the constitution and I had to skip," he said, contracting his earlier version.
Moments after Raila took oath, a frustrated Kalonzo claimed that police had put him under house arrest hours to the function.
At a rally in Machakos last month, Raila warned NASA leaders against focusing in 2022 adding that they should first handle the 2017 debacle.