Governor Alfred Mutua returned to the country on Saturday after a month-long trip abroad and launched a scathing attack on Cord Co-Principal Kalonzo Musyoka.
Dr Mutua in his official Twitter and Facebook accounts told the former Vice President to show his development score card to the people of Ukambani and stop "idle talk".
"Recently, I travelled abroad and I have positive results from that tour," Mutua said.
"Three fruit factories, a pharmaceutical company and a car assembling plant are ready to set up base in Machakos County. I also bagged 2,000 job opportunities for my youth. I will not stop there. I will continue to focus on the growth of my people. I welcome all leaders to embrace servant leadership and I am ready to work with anyone with a progressive mindset who shares in our ideology that puts our people first."
Last week on Saturday, Kalonzo while addressing a rally at Kyandu Academy in Kyevaluki, Kangundo sub county accused Dr Mutua of abandoning the people of Machakos by staying out the country for more than a month.
"I have not heard of an elected leader staying away from his country for that long," Kalonzo said then.
"Therefore, he should come back home. If not, as a party leader, I will accuse him of abdication of responsibility where the party will take an advisory opinion."
He accused Governor Mutua of being used by the Jubilee administration to divide the Kamba community.
Present at the event at Kyandu was Deputy Governor Bernard Kiala. Mr Kiala said if the governor did not return within seven days, he would take over the county's leadership as the governor.
Kalonzo, who has had a frosty relationship with the Mutua said there were pending development projects in the county which needed to be completed and that for the county boss to spend over 30 days outside the country was uncalled for at such a time.
But Mutua who after arrival met MCAs and headed for a rally in Mwala town said: "I request [Kalonzo Musyoka] to publicly declare his development score card for the region. Leaders need to be accountable to voters and should only be supported based on what they have done for [them]."
Mutua according to sources from the county government toured Tanzania, Dubai and Indonesia.