ODM leader Raila Odinga and Ford Kenya's Moses Wetang'ula will share a podium at Kofi Annan's burial in Ghana on Thursday.
Raila jetted out via Dubai on Tuesday evening while Wetang'ula left through a direct flight to Ghana on Wednesday morning.
The Bungoma Senator told the Star before departing JKIA that they cannot export their differences to Ghana.
"This is a very sombre and respectable event. It's not an event in which we can export our Kenyan competition and parade ourselves," Wetang'ula said.
Wetang'ula is expected to meet Ghanaian President Nana Akufo-Addo.
"Annan shall be remembered as the first black African to ascend through the ranks of the UN to become secretary-general," Wetang'ula said.
He eulogised Annan, who was the UN secretary general between 1997 and 2006, as a great son of Africa.
Wetang'ula and Raila - both NASA principals, fell out after the mock swearing-in of the ODM leader as the People's President at Uhuru Park on January 30.
Their differences deepened when Wetang'ula was ejected as the Senate's Leader of Minority.
Annan was instrumental in brokering a peace deal that saw the formation of the grand coalition government following Kenya's post-election violence of 2007/08.
He mediated the dispute which arose following the December 2007 poll alongside former Tanzania President Benjamin Mkapa and Graca Machel.
Other eminent leaders, among them former Ghanaian president John Kufuor and current SA President Cyril Ramaphosa , were also involved in bringing together Raila and retired President Mwai Kibaki to a common understanding on the divisive election.
Annan died in Switzerland on August 18 aged 80 years.
Senate speaker Kenneth Lusaka is the leader of the Kenya's official diplomatic delegation that comprises former PM Raila; Murang'a Woman Representative Sabina Chege; Ag High Commissioner of Kenya to Nigeria (also accredited to Ghana) Linus Ogola; among other officials from the Ministry of Foreign Affairs.
He said Kofi Annan's name will remain etched in Kenya's history as he chaired The Panel of Eminent African Personalities, that steered the 41-day peace process in the aftermath of the chaotic polls.
Annan will be laid to rest on Thursday.
The funeral service will be at AICC Church followed by a private burial at the Military Cemetery. The departed diplomat with be treated to full military honours and a 17-gun salute.