Kenya's President Mwai Kibaki has ordered an inquiry into corruption as a graft scandal engulfs his government.
Donors doubt Kibaki is still committed to fighting corruption
Mr Kibaki was elected in 2002 on a pledge to clean up government but many Kenyans doubt he remains so committed.
An audit of the country's security contract bidding process was launched last year after protests over a $34m deal given to a French firm.
The report has revealed details about how contracts are awarded that Mr Kibaki says must be examined.
Two ministers have threatened to resign and Vice-President Moody Awori admits there is "massive corruption" at senior levels.
The US has already suspended funding to Kenya and the EU has warned that corruption must be tackled.
'Top brass' involvement
Mr Kibaki said the audit had raised questions, and told Kenya's anti-corruption commission "to move with speed and act appropriately... to ensure there is no loss of government funds".
Health Minister Charity Ngilu said that if corrupt ministers did not leave, the entire cabinet should be sacked.
First Planning Minister Peter Anyang' Nyong'o backed her call.
"The president must take decisive action to save the government and the country from this ignominy," he said.
The EU has warned that aid could once more be suspended if corruption is not tackled.
Most donors cut off aid under former President Daniel arap Moi, citing corruption. They restored funding under Mr Kibaki.
"We share the deep concern evidently felt by the Kenyan people about the lack of good governance within the government of Kenya and the damage it causes to the nation's welfare and the effective operation of its institutions," the EU said in a statement.
The president's top anti-corruption adviser, John Githongo, resigned earlier this week.
On Wednesday, a former colleague told the BBC she had spoken briefly to Mr Githongo since his resignation and that he felt the government, and President Kibaki, was no longer committed to stopping corruption.
Following Kibaki's election, there was a high-profile campaign against corruption
Mr Githongo, a veteran anti-corruption campaigner under Mr Moi, was appointed just a month after Mr Kibaki's inauguration, to oversee his fight against corruption.
Following Mr Githongo's resignation, the US announced it was suspending funding for Kenya's anti-corruption efforts.
Last week, UK High Commissioner to Kenya Sir Edward Clay said "massive looting" was continuing and that he knew of at least 20 dubious public contracts.
But Justice Minister Kiraitu Murungi warned diplomats not to behave as "local partisan political activists".
In apparent reference to Mr Githongo, he said: "We cannot fight corruption by running away."
A Transparency International survey of perceived corruption rated Kenya 122nd out of 133 countries in 2003.
Public hearings into Kenya's biggest ever corruption investigation, which has become known as the Goldenberg affair, have finished nearly two years after the first witness gave evidence.
The inquiry looked at how the previous government of President Moi paid out hundreds of millions of dollars during the early 1990s for non-existent exports of gold and diamonds.