Chief Kenya mediator Kofi Annan has suggested that he might send a list of suspected election violence ringleaders to the International Criminal Court.
He said he would obey the “spirit, letter and intent” of a commission of inquiry into the violence.
The commission delivered a sealed list of suspects to Mr Annan and said it should be sent to the ICC if a local tribunal was not set up by 1 March.
Parliament on Thursday rejected a bill to establish the special court.
Some 1,500 people were killed after political and ethnic rivalries caused clashes around the country following the disputed December 2007 elections.
Many MPs said they did not have faith in Kenya’s justice system and that those involved in the violence should be tried at The Hague.
Mr Annan, who brokered a power-sharing deal to end the violence, said he was disappointed in the parliamentary vote.
“I believe it is also a blow to efforts aimed at ending the culture of impunity in Kenya,” said the former UN secretary general.
Under parliamentary rules, the bill cannot be re-introduced to parliament until six months have elapsed.
The BBC’s Anne Mawathe in Nairobi says the government could possibly ask for more time to establish the local tribunal.
After Thursday’s vote, Minister for Nairobi Metropolitan Development Mutula Kilonzo, who was part of the mediation team that crafted the power-sharing agreement, said the president and prime minister had let down the country and should resign.
President Mwai Kibaki and Prime Minister Raila Odinga attended the session of parliament to lead the vote in favour of the bill.
The bill required the support of 145 MPs to be passed, but only 101 MPs voted in favour.
The opposition to the bill came from MPs who support both Mr Kibaki and Mr Odinga.
But Justice Minister Martha Karua said the rejection of the bill was a “collective failure”.
“We have abdicated responsibility as a National Assembly. When we say The Hague, we are saying only those who bear greatest responsibility are going to be tried. We are saying the rest should go scot-free,” she said.
Widespread clashes broke out after Mr Odinga said the results of the December 2007 election had been rigged in favour of the president.
After weeks of talks led by Mr Annan, in February 2008 the rivals agreed to share power to bring an end to the violence.
In December 2008, the Electoral Commission of Kenya, which presided over the controversial poll, was disbanded by parliament following recommendations by another inquiry into the voting process.