Kalonzo said they will on Wednesday move to the High Court to challenge IEBC's decision to bar Sonko from contesting.
He criticised the electoral body's decision saying it was unfair.
"The Independent Electoral and Boundaries Commission cleared Sonko to run for Nairobi governor in 2013. They are now blocking him aimlessly," Kalonzo said.
He spoke on Tuesday when he led Wiper leaders to visit the razed Grogon market in Machakos town.
The Wiper leader said those blocking Sonko don't want him (Kalonzo) to have power in Mombasa and the entire Ukambani.
"I looked at the panel constituted by chairman Wafula Chebukati. Chebukati said he won't clear Sonko. How is it possible that Chebukati and his servants are a kangaroo court.
"I want you to know that we will move to court. Sonko must be in the ballot for Mombasa gubernatorial race," he said.
Kalonzo said the case is political witch-hunt and Sonko must be Mombasa governor.
"There must be equality before the law. This country will be strictly run in accordance to the rule of law, no jokes.
"I want our judges to demonstrate that they are also nationalists. They will uphold the rule of law and should leave these IEBC jokes," he said.
The Wiper leader said Sonko and his lawyers are preparing court documents.
"He (Sonko) will return the papers tomorrow in a Mombasa court," he said.
Kalonzo said Mombasa people need revolutionary change.
"They didn't talk of impeachment because he has an active case in the Supreme Court," he said.
Azimio presidential candidate Raila Odinga and Kalonzo donated Sh3 million to Machakos fire victims.
Raila donated Sh2 million, while Kalonzo gave Sh1 million cash to traders who lost their property to the Grogon market inferno, weeks ago.
The donations were presented to the victims by Kalonzo.
He was accompanied by Machakos gubernatorial candidate Wavinya Ndeti, Senator Agnes Kavindu and Woman Representative Joyce Kamene.
Also present were MPs Patrick Makau (Mavoko), Stephen Mule (Matungulu) and Robert Mbui (Kathiani).
Wavinya gave her personal donation of Sh500,000, while both Kamene and Kavindu donated Sh100,000 each.
(Edited by Bilha Makokha)
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