A group of more than 200 Somali MPs are stranded in the Kenyan capital a week after attending a regional summit.
The MPs say the organisers of the summit have refused to cover their travel expenses back to Somalia.
They are living in hotels around Nairobi while they wait for the matter to be resolved.
The regional meeting was held to review the performance of Somalia's transitional government, nine months before its mandate expires.
The government was strongly criticised for failing to bring peace to Somalia, which has not had an effective national government for 17 years.
The government needed Ethiopian troops to oust Islamist forces from Mogadishu but they continue to stage attacks.
One of the MPs told the BBC's Network Africa programme that the Inter-Governmental Authority on Development (IGAD) was supposed to pay their expenses and arrange their flights back to Somalia.
Abdul Rashid Mohammed Iro said the UNDP had paid for 27 MPs to fly back to Mogadishu on Thursday.
But the UNDP denied involvement in the matter and said had not paid for any flights.
"If someone invites you, he has to cover your expenses and your transport. That's why we are expecting IGAD to cover our expenses and transport," Mr Iro said.
He said that the European Union had also pledged to cover their expenses.
The MPs were now trying to pay for their expenses themselves and go back to Somalia, Mr Iro said.
"We are trying to solve our own problems. Sometimes we get paid a salary on monthly basis but the last three months we didn't get any pay," he said.