Nairobi — Wrangles within Kenya's government have deepened after a senior cabinet minister quit in what appears to be the clearest sign yet that President Mwai Kibaki's wing of the ruling coalition is frustrating the reform agenda.

Justice and Constitutional Affairs Minister Martha Karua, until recently a hawkish Kibaki ally, quit in a huff on Monday, saying her position was "untenable following recent decisions in the ministry."

Karua's party, NARC-Kenya, is a junior partner allied to Kibaki's Party of National Unity (PNU). On Tuesday, NARC-Kenya secretary general, Danson Mungatana, also resigned as an assistant minister.

President Kibaki last week appointed five High Court judges and promoted two others to the Court of Appeal allegedly without consulting Ms Karua. The president swore-in the judges in the absence of Ms Karua. She and the Law Society of Kenya said some of the appointments were not on merit.

For days, Ms Karua publicly stated that senior officials at the presidency were frustrating key reforms recommended in the National Accord that created the coalition government in the violent aftermath of the 2007 election believed to have been rigged by Kibaki.

Ms Karua has been backing calls for the resignation or sacking of Kenya's much-maligned Chief Justice, Evan Gicheru, and Attorney General, Amos Wako. She had the support of Prime Minister Raila Odinga, Kibaki's coalition partner. Kibaki supports the Chief Justice.

Her departure comes hot on the heels of failed talks at the weekend between PNU and Odinga's Orange Democratic Movement (ODM). The partners differed sharply on the agenda of the meeting which was attended by the president and the Prime Minister on Saturday.

Analysts are predicting collapse of the one-year-old coalition which has been repeatedly accused of failing to deliver on key pledges.Protestant and Anglican churches have called for fresh elections.

Prime Minister Odinga on Monday delivered his harshest criticism of Kibaki so far, describing the president's leadership style as "primitive." ODM has consistently claimed that it has been short-changed in power-sharing by Kibaki's PNU.

Ms Karua is the first minister to resign from the coalition government.