"The bill is aimed at paving the way for the establishment of a special tribunal that will seek accountability against persons bearing the greatest responsibility for crimes against humanity relating to the 2007 general elections," it said.

"The agreement is signed by both President Mwai Kibaki and Prime Minister Raila Odinga.

Map

Kenya's maize crop affected by post-election violence

"The parties shall also ensure that any person convicted of a post-election violence offence is barred from holding any public office or contesting any electoral position."

The violence followed a disputed presidential election, but was dispensed along ethnic lines.

Kibaki claimed victory in the December election but Odinga, who had been leading in polls, said that fraud had taken place and the poll hijacked.

Kofi Annan, the former UN secretary general, helped to mediate the signing of a peace deal in February in which power was shared between Kibaki and Odinga, appointed as president and as prime minister respectively.

A commission to investigate the involvement of political parties and government security forces in the violence was set up in May and recommended a special court be established.