Some 27 federal MPs and several former and sitting state presidents throw their weight behind the electoral office.
Kenya has criticised the United Nations for making "insensitive" demands on Somalia's Jubbaland electoral agency which is due to preside over a presidential poll on Thursday.
Foreign Affairs Cabinet Secretary Monica Juma said the "unattainable" demands the United Nations Assistance Mission in Somalia (Unsom) is making on the Jubbaland Electoral and Boundaries Commission (JIEBC) must be withdrawn because they risk splitting the state.
The Somali state shares a boundary with Kenya.
The Thursday election has been punctuated with calls for more time for candidates to register.
In a letter to UN Under-Secretary for Political Affairs Rosemary DiCarlo, Juma said the commission has already made too many concessions.
"The election in Jubbaland cannot be expected to be perfect. However, the JIEBC has, in the face of daunting challenges, done its best to ensure that the vote is as fair, inclusive, transparent, credible and humanly as possible," the Cabinet Secretary wrote on Sunday.
"Kenya is concerned that the UN holds a position that is insensitive to the circumstances within which the Jubbaland elections are being conducted."
She accused Unsom boss James Swan of making selective demands on JIEBC "while not doing the same to its critics".
Ahead of the federal state presidential poll, Swan fronted calls for more days for candidates to be registered.
Last week, the commission agreed to add 72 more hours for presidential hopefuls to do so.
After it closed the registration on July 26, some aspirants pleaded with the international community to push for more time and relaxing some of the conditions set by the poll agency.
On Monday, JIEBC chairman Hamza Barre rejected calls to extend the reopened window for candidate registration, insisting that the election would go on as planned.
The commission said it consulted everyone involved in the poll before deciding the three-day window was sufficient for those hopefuls who felt left out.
Some 27 federal parliament MPs, Puntland State President Said Abdullahi Dani, former Galmudug State President Abdulkarim Gulled and ex-Somali presidents Hassan Sheikh Mohamud and Sheikh Sharif Ahmed have endorsed the work of the commission.
"There are no additional steps required to improve the process as necessary measures were taken. The commission believes constitutional and legal requirements were fulfilled on the conduct of electoral process in line with constitution and electoral laws," Barre said on Sunday in a letter addressed to Swan.
"We decided the process of electing the president to continue as planned."
In the formal list, incumbent Sheikh Ahmed Islam Madobe will face Mohamed Omar Gedi, Mohamed Abdille Magan, Anab Mohamed Dahir, Abdi Hiis Udan, Ahmed Abdi and Abdirahman Ahmed Rabi. The final list is due on Wednesday evening.
It emerged Tuesday that while Swan claimed to be making demands on behalf of the international community, Nairobi said there had been no consultations.
Swan had said he was speaking for the UN, the Inter-Governmental Authority on Development, Italy, Kenya, Denmark, the US, Belgium, the Netherlands, Sweden, Austria, Ireland, the European Union, France and the UK.
He had pleaded for more days for candidates to register, arguing that participation would minimise the risk of violence.
The JIEBC has already sworn in 73 MPs, out of the possible 75. The two last remaining slots had been vacant after elders who were to nominate the MPs, refused to take part.
On Monday, one of the protesting elders, Ugas Hussein Mohamoud Qorane, returned to the commission saying he was doing so for the sake of peace and stability.