In various TV interviews, Ruto maintained although a sitting deputy president, he was rendered jobless and Matiangi given his responsibilities.
But Matiang'i who started in the ICT docket before he was moved to education and later interior hit back at Ruto calling him a liar.
In a hard-hitting statement, Matiang'i asked Ruto to state which job he had taken away from him.
Matiang'i said the President only gave him the responsibility of coordinating government projects, which he has done perfectly for the last three years.
"Those complaining let them explain what job I took from them. I am suffering restraint for ethics of conduct and collective responsibility, however, this political hypocrisy should be stopped..." Matiang'i said.
Matiangi maintained that as a CS he was dedicated to the directives given by the President, then Uhuru Kenyatta.
In 2021, Matiangi found himself on the receiving end after the security of Ruto was allegedly removed. As Ruto's allies sought answers over the issue, Matiang'i appeared before members of parliament and said of all Kenya's holders of the number two job, Ruto had the biggest security detail dedicated to him at 257 officers.
"We are not jokers, there was no withdrawal, but a rearrangement of the security by the Inspector-General of Police. The decision was not whimsical because many considerations were made," he said.
Matiang'i questioned why queries came up when the changes were made to Ruto's security detail, saying it was not the first time such changes were being made.
He said the changes were being politicised for political sympathy in favour of Ruto.
He later went on to list all the properties that Ruto owned and the number of security personnel attached to them, a move that saw a section of MPs threaten his impeachment.
During the 2022 presidential debate, Ruto claimed that police reservists in the troubled Kerio Valley were withdrawn to punish him.
But Matiangi hit back saying, "There has never been security withdrawal of police anywhere. This is just petty politics. Some people have mastered lying and has become their career. The only truth about themselves is their name."
Ruto hit back saying Matiang'i had become dishonest to himself.
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He said, although Uhuru had assigned them responsibilities, it did not mean they had to lie and demean others.
He further accused the CS of hatching a plan to deny him victory in the August 9 election.
An agitated Matiang'i responded dismissing the claims.
"We are only delivering that which we are supposed to. Some people now need to be licensed for telling lies and poisoning Kenyans. You cannot be a sitting deputy president presiding over functions and then say someone is punishing you," he said.
Matiang'i said in fact it was laughable that a person who relied so much on lies was seeking a public office.
Matiang'i further dismissed claims that some Cabinet Secretaries were out to rig the August 9, General Election.
The CS said those who are complaining should admit they are in panic mode and trying to find ways to seek sympathy votes.
"It is this usual hypocrisy and pretence in our political environment. In 2017, I was on the campaign trail with all of them. So, did I become a CS in 2022, [and not in 2017]? They did not raise the issues when we were campaigning with them," said Matiang'i.
He added, "I was with some of those who are raising issues now. I hit the campaign trail with them, and even addressed roadside gatherings, including here in Kenyenya Market. I attended meetings with them in South Mugirango, Gesima. The internet does not forget. Go and look for videos of rallies that I attended with them."
Matiang'i said now because the CSs are not with them, they are deemed to be breaking the law.
While maintaining that the CSs have a right to give their views on politics which should not be construed to mean they are out to interfere with the polls, he said the government is ready to back up the IEBC in whichever way they'll need.
JOE MUCHERU
The ICT Cabinet Secretary had also on various occasions been in bad books with the future president.
As we drew closer to the general election, Ruto allies hit at Mucheru accusing him of being among those who were planning to scuttle the process.
The said Mucheru as the man in charge of connectivity, was planning in partnership with other players to shut down the internet.
"We need to get more serious, don't look for work you do not want to do because Kenyans are watching and that is why they will elect Raila Odinga come August 9, General Election," he added.
Additionally, Munya said the Jubilee administration had accomplished more in its second term compared to its first term when Ruto said he participated actively in government.
"Most of the work was done during Uhuru's second term in government, the first term was marred with corruption," Munya said.
Comparing his tenure as Agriculture minister and that of Ruto in the same docket from 2008 to 2010, Munya argued that he had outperformed the future president.
"Even Ruto was once the Agriculture CS but he did not create the National Cereals and Produce Board (NCPB) yet he is roaming around every day," Munya said.
In one of his rallies, Munya confronted a crowd that heckled him after he started talking about Ruto's shortcomings.
"You say that I should leave him [Ruto] alone, is he your father? If you want to attend his rally, then leave. You are well aware that I am not supporting him [for the presidency], why did you attend this meeting," he posed.
KERIAKO TOBIKO
Two years before the August 2022 General Election, Environment CS Keriako Tobiko criticised Ruto for campaigning and neglecting his role as the Deputy President.
Tobiko challenged Ruto to shelve his campaign and instead help former President Uhuru serve the nation.
"The office of the President is still not vacant, we still have two years away to 2022, why are people hosting delegation at Karen," he said.
The CS, seemingly unamused by Ruto's speech, said the deputy president cannot openly defy the president, while still holding office in the same government.
Wamalwa went ahead to claim that Ruto almost slapped him in 2018.
Speaking during an Azimio la Umoja - One Kenya coalition rally at Bukhungu stadium in Kakamega, Wamalwa stated that the DP nearly slapped him for leading a delegation from Western Kenya to Statehouse without informing him.
But Ruto responded with a devastating repartee.
Deputy President William Ruto dismissed him thus: "I heard a certain guy claiming that I wanted to slap him. Where I come from, we don't slap women. Please, let him know that".