Reuters reports: President Barack Obama will nominate former Republican Senator Chuck Hagel to be his defense secretary and an announcement could come on Monday, a Democratic congressional aide said.

The choice will likely set up a confirmation battle in the Senate over whether the former Nebraska senator and Vietnam veteran is a strong enough supporter of key U.S. ally Israel and over his past calls for military cuts.

The Obama administration backed down from a tough Senate confirmation battle over Susan Rice, the U.S. Ambassador to the United Nations, who was Obama’s first pick to replace Hillary Clinton as secretary of state. Rice withdrew her name from consideration after drawing heavy fire from Republicans for remarks she made in the aftermath of a September 11 attack on the U.S. mission in Benghazi, Libya.

“The administration has a lot of work to do on Hagel,” a Democratic Senate aide said.

“He is in a weaker position now than Rice ever was because Rice would have rallied Democrats behind her. The administration floated Hagel’s name, then neglected to defend him effectively when his critics started taking shots,” the aide said.

However, the White House is confident it can weather criticism of Hagel’s record and garner enough votes from both sides of the political aisle to get his nomination through committee and win confirmation in the Democratic-led Senate.

“The president wants him, because he trusts him and he’s an independent voice,” a source close to the situation said.

The source said Hagel had received high-level messages of reassurance in recent days that his nomination was on track despite a campaign by his critics aimed at derailing it.