Some 80 Kenyan MPs stormed out of parliament on Thursday in the latest twist in a row over a new constitution.
Delays at implementing the new constitution sparked riots
MPs of the opposition Kanu party and LDP staged the walk-out after a bill was passed to allow constitutional changes with only a simple majority.
Observers say the government intends to reduce prime ministerial powers provided for in the new constitution.
President Mwai Kibaki's National Rainbow Coalition came to power in 2002 on a pledge for constitutional change.
The LDP is part of the National Rainbow Coalition but is at the forefront of attempts to get a new constitution, after its leader, Raila Odinga, was promised the new post of prime minister.
Delegates have spent months drafting a new constitution but this has not yet been implemented.
In July, there was rioting in Nairobi and Kisumu after a deadline was missed, in which one person was killed.
Previously, a two-thirds majority was needed to make changes to the constitution.
But now changes can be made with a simple majority, which led Kanu leader Uhuru Kenyatta to accuse President Kibaki of reneging on his promise to give Kenyans a people-driven constitution.
"We are not going to participate whatsoever because he is trying to use a clique of his friends to amend the constitution through the backdoor," he said, The Standard newspaper reports.
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"We are frightened that under a democratically-elected government of Hon Mwai Kibaki we can wake up tomorrow and find that we have a new constitution," MP Otieno Kajwang said.
But assistant Minister for Justice and Constitutional Affairs Robinson Githae told KTN television station that Thursday had been "the happiest day for this country".
"Today was the day that we saw the people who want to give Kenyans a new constitution and the ones who don't want to give Kenyans a new constitution," he said.