Senator John McCain
Senator John McCainReuters

President Barack Obama's choice to lead the Pentagon, former GOP Senator Chuck Hagel, will likely be confirmed next week, one of his most fierce opponents said on Sunday.

Speaking to NBC’s “Meet the Press”, Senator John McCain (R-Ariz.) said, “I’m confident that Senator Hagel will probably have the votes necessary to be confirmed as secretary of defense.”

After Senate Republicans voted last week to sustain a filibuster and block the former Nebraska senator's nomination from advancing toward confirmation, McCain acknowledged that Hagel will likely win confirmation once the chamber returns from its recess.

“No, I don’t believe he’s qualified, but I don’t believe that we should hold up his nomination any further, because I think it’s (been) a reasonable amount to time to have questions answered,” McCain said of the week-and-a-half-long window which Senate Republicans demanded to pore more thoroughly over their former colleague's records.

McCain denied that Republicans' attacks on Hagel were personal in nature.

"99 percent of it has to do with the positions Senator Hagel has taken," he told “Meet the Press”.

Republicans have demanded more details on Hagel’s finances and on Obama's management of a September attack on the U.S. consulate in Benghazi.

Hagel's critics have also said they are worried by his past remarks and voting record on Israel, Iran and other issues.

The Republican Jewish Coalition, along with countless others, has cited a long list of Hagel’s anti-Israel policies, asserting that his nomination would “be a slap in the face for every American who is concerned about the safety of Israel.”

Hagel recently claimed that there is "not one shred of evidence that I'm anti-Israeli, not one (Senate) vote that matters that hurt Israel."

"I didn't sign on to certain resolutions and letters because they were counter-productive and didn't solve a problem," he said.

Hagel faced fire from Republicans at his confirmation hearing over his past anti-Israel remarks and his attitude towards Iran. These included past comments he made that there’s no justification for Israel to "keep Palestinians caged up like animals."

The American Jewish Committee (AJC) has called for “further Senate deliberation” on Hagel due to his highly contentious views on Israel and the Middle East.

“[I]n light of his complex record in the Senate and controversial statements he has made since his public service on strategic and political affairs – notably grappling with the range of pressing Middle East issues – AJC believes that further Senate deliberation is called for before any final vote is taken,” affirmed AJC Executive Director David Harris in a statement.

"[W]e feel it especially important that Senator Hagel be given a full opportunity to clear the air, so that the Senate can have a more thorough picture of the nominee's views,” continued the AJC.

Obama criticized the Republican members of the Senate on Thursday, shortly after they blocked Hagel's nomination.

"We've never had a Secretary of Defense filibustered before…there are only a handful of instances in which there's been any kind of filibuster of anybody for a cabinet position in our history," Obama said, adding, "My expectation and hope is that Chuck Hagel, who richly deserves to get a vote on the floor of the Senate will be confirmed as our defense secretary.”