The Foreign Minister, Alexander Downer, and the Trade Minister, Mark Vaile, may be called before the Cole inquiry into the AWB kickbacks scandal.
Lawyers assisting the inquiry have asked the ministers to provide statutory declarations outlining what they knew about wheat payments made to the former Iraqi government of Saddam Hussein.
Senior counsel assisting the inquiry, John Agius SC, says if he needs to call the ministers to give evidence after reading their statements, he will.
But Labor's foreign affairs spokesman, Kevin Rudd, says under the present conditions, even if the inquiry does find evidence of wrongdoing by government ministers, it cannot make any findings against them.
"Unfortunately, Commissioner Cole has limited terms of reference so that if these ministers appear and in the statements they make, Commissioner Cole is going to be extremely limited in what determinations he can make about these ministers and how they did their job."