Afghanistan's president, Hamid Karzai, was dealt a painful political blow yesterday when the country's parliament rejected 70% of his nominees for a new cabinet, including a regionally powerful warlord and the only female minister.

The secret ballot of MPs, which came at a crucial point in Karzai's quest for legitimacy in the eyes of Afghans and the rest of the world, resulted in the rejection of 17 out of 24 of his nominees.

The most high-profile scalp was that of the water and power minister, Ismail Khan, a warlord in the western province of Herat during the 1990s civil war who is accused of corruption and human rights abuses. Critics say he is an example of how the president remains beholden to regional powerbrokers.

"I think, unfortunately, that the criteria were either ethnicity or bribery or money," MP Fawzia Kufi said of many of the names put forward by Karzai in the middle of December.

The rejection of the women's affairs minister, Husn Bano Ghazanfar, was another awkward blow to Karzai, who has pledged to place more women in senior government posts.

The nominations were meant to keep 12 ministers in their posts for a second term and appeared, in part, to be aimed at satisfying US and western wishes that trusted hands be retained.

Karzai is believed to have hoped to put a new cabinet in place by the time an international conference on Afghanistan takes place in London on 28 January. Of the seven nominees approved during yesterday's voting by more than 200 MPs, all but one are currently cabinet ministers.

The Afghan president, who visited the southern province of Helmand yesterday to express his condolences to relatives of civilians allegedly killed in a Nato air strike on Wednesday, has pledged to make new nominations for the empty posts but it was unclear when those names will be announced, or when a parliamentary vote will be held.

The chief of Afghanistan's elections commission said parliamentary elections will be held on 22 May, just 10 months after Karzai's victory in a presidential vote marred by fraud and violence.