Maathai, who won the Nobel Peace Prize in 2004 for her environmental campaigning, defected to a smaller party after she was defeated by a rival who will run on President Mwai Kibaki's Party of National Unity (PNU) ticket in Tetu, central Kenya.

Among other big names who failed to secure a PNU nomination on Friday to contest in a parliamentary election due on December 27 was former Internal Security Minister Chris Murungaru.

Murungaru, once seen as a powerful Kibaki ally, was barred from entering the United States and Britain in 2005 because of high-level corruption allegations.

Kenya's anti-graft body recommended last year that he be prosecuted over the so-called Anglo-Leasing affair, one of the country's biggest graft scandals involving some $300 million.

Party primaries held across the east African country were plagued by delays, lack of voting materials, numerous scuffles and several incidents of more serious violence.

In restive Mount Elgon region near the border with Uganda, gunmen ambushed a vehicle carrying ballot boxes, shooting and wounding seven people, including three policemen.

Local newspapers denounced the exercise as a "fiasco" and a "national disgrace".

Kenya's presidential election will also be held on December 27, and polls published over the weekend showed it shaping up to be the closest yet in east Africa's biggest economy.

The Strategic Research poll gave opposition leader Ralia Odinga 49 percent to Kibaki's 38 percent, almost unchanged, while Infotrak Harris had Odinga on 47.3 percent 37 percent -- indicating a big jump in support for Kibaki.

A poll by Consumer Insight had Kibaki overtaking Odinga with 41.4 percent to 40.7 percent for the first time since the polls were first published eight weeks ago.