The three presidential contenders will be listening when Petraeus and U.S. Ambassador to Iraq Ryan Crocker testify Tuesday before the Senate Armed Services and Foreign Relations committees, The Washington Post (NYSE:WPO) said Monday. Petraeus is expected recommend that once the current troop drawdown ends, a pause be instituted for reassessment.

Sens. John McCain, R-Ariz., Hillary Clinton, D-N.Y., and Barack Obama, D-Ill., are expected to be among the questioners. McCain is the presumptive GOP nominee; Clinton and Obama are battling for the Democratic nomination.

"This is sort of a dress rehearsal for who is best prepared to be commander in chief, who has the best understanding of what has happened, what was wrong in Iraq and how to fix it," said McCain supporter Sen. Lindsey Graham, R-S.C., who is on the Armed Services Committee.

Foreign Relations Committee Chairman Joseph Biden Jr., D-Del., said he doesn't want the hearing to become politicized.

"The biggest mistake we could make is politicizing this, looking at this in terms of political advantage," he said. "The American people are sick of this."