The challenger in Afghanistan's recent presidential election said Wednesday that President Hamid Karzai has come to power illegally and will not be able to rein in corruption or serve as a reliable partner in the fight against the Taliban.

Former Foreign Minister Abdullah Abdullah spoke a day after five British soldiers were killed in a shooting in southern Helmand province. Afghan authorities said the attack was carried out by an Afghan policeman who opened fire on the British troops.

Abdullah said the Afghan government had squandered eight years of opportunity and the assistance of its Western allies by failing to stop corruption or create a government that responds to the needs of the Afghan people.

The Afghan election commission's decision not to have a runoff election after a fraud-marred first round was not legal and has created a government that cannot be trusted to obey laws, Abdullah said.

"That government cannot bring legitimacy, cannot fight corruption," Abdullah said, adding that it "cannot deal with all the challenges, especially the threat of terrorism, security problems, poverty, unemployment and many others."

But Abdullah — who said he dropped out of the election runoff because it could not be conducted freely or fairly — said he was not personally challenging the commission's declaration of Karzai as president.

"The process has completed itself with that final, illegal decision," he said, referring to the commission's ruling.

"I leave it to the people of Afghanistan to judge," he said.

The election commission proclaimed Karzai the victor of the country's tumultuous ballot on Monday, canceling the planned runoff and ending a political crisis two and a half months after a first round of voting in August was marred by widespread fraud.

People close to Karzai and Abdullah have said that the two have been in talks over the last few weeks to negotiate a power-sharing agreement, but no deal has emerged.

Karzai said in his victory speech Tuesday that he would welcome anyone from the opposition into his administration, but did not make a direct appeal to Abdullah to join him.

Asked why Karzai did not mention Abdullah in his speech, a spokesman said the president no longer considers Abdullah his main opponent because he dropped out before the runoff.

"Dr. Abdullah withdrew from the process in the middle of it," Humayun Hamidzada said.

Abdullah reiterated Wednesday that he does not want a place in Karzai's government and said he has not asked for Cabinet or ministerial positions for his allies. He said the last time he spoke directly with Karzai was a week ago.

"In this environment I would rather act like a pressure group," Abdullah said. Asked what recommendations he would make to clean up the government, Abdullah said he had not yet formed a specific list of demands.

Abdullah appears to be setting himself up as an opposition leader in a country where political parties are not strong and there has never been a vigorous political movement in opposition to the president. Karzai has repeatedly said that political parties are too divisive for war-scarred Afghanistan and described himself as an independent open to working with everyone.

Karzai pledged Tuesday to banish corruption by revising laws and strengthening a corruption investigation commission that was established a year ago, but did not get more specific about what needs to be done.

Hamidzada said the government is working on a concrete plan to combat corruption, but declined to provide details.

"He is going to continue the fight against corruption and expedite and redouble efforts," he said.

Asked about the wider allegation that the government has done little to help the Afghan people, Hamidzada said Afghans' lives have improved in measurable ways: literacy is up and many more people are able to attend school and get medical care than when Karzai first took office.

As for security, he said it was unfair to judge Karzai in the middle of a difficult push to fend of the Taliban.

"We are in the middle of a fight, a war. We have a problem and that's why we have more than 40 countries helping us," Hamidzada said.

He added that Karzai also plans to strengthen his roster of advisers to create a more "professional Cabinet," a suggestion that the president could bring in more technocrats.

"There are a number of capable people right now, and he will strengthen his Cabinet with new people," Hamidzada said.