Musyoka withdrew from his bid for the presidency and returned to the Declaration coalition after accepting the post of cabinet secretary general by Raila Odinga.
Speaking at a press conference on Thursday, Kalonzo said he reached the decision after extensive consultations with party officials.
He announced that he had postponed his bid and would fully support Odinga’s campaign.
“After much consultation, I humbly humbly accept my appointment as Prime Minister of the One Resolution Kenya,” he said.
He also announced that he was traveling to Mukuru Kwa Njenga where he would address a joint meeting with Raila, Karua among leaders and other members of the coalition.
Kalonzo was surrounded by a number of front-facing mirror operators, and KANU President Gideon Moi, who would lead the intense talks that saw Kalonzo join the Declaration.
The Wiper leader also congratulated Narc Kenya leader Martha Karua on her election as a co-candidate for the Declaration coalition, pledging full support for their alliance with the coalition.
“I am involved in the Declaration One Kenya campaign because our goal is to win,” he said.
Last month, Kalonzo announced he would run for the presidency in the August 9 election, after the party severed ties with the Raila Odinga-led Declaration coalition.