The ministers had provided sworn statements to the inquiry on Wednesday outlining their knowledge of the $300 million in kickbacks allegedly paid.
Counsel assisting the inquiry John Agius SC said Mr Vaile would be called to face the inquiry on Monday, followed by Mr Downer on Tuesday.
"I expect that they will give evidence based upon the statements. There are one or two matters I wish to take up with them." Mr Aguis said.
Mr Agius said applications had also been received to cross-examine both ministers on behalf of lawyers acting for AWB's former managing director Andrew Lindberg and executives Peter Geary and Michael Long.
Commissioner Terence Cole said he would consider the applications over the weekend, before deciding on whether to allow the lawyers representing the AWB executives to cross-examine the ministers.
Outside the inquiry, a spokesman for AWB said lawyers representing the company haven't made any application to cross-examine the ministers.
Earlier, Prime Minister John Howard said he had copies of the ministers' statements but that he had not yet had time to read them.
Happy to appear
Both Mr Vaile and Mr Downer have indicated that they are happy to appear at the inquiry.
"There is no smoking gun and this is not a victory for the opposition," Mr Vaile said.
"If there is a victory anywhere it's that the government from the outset was prepared to establish this inquiry to ensure that the good name of Australia was protected in international circles," he added.
A spokesman for Mr Downer said the minister had said all along he would welcome an invitation to appear before the commission.
The inquiry's terms of reference limited it to investigating potential illegal activities by AWB and not actions by government officials.