Sen. Dick DurbinRichard (Dick) Joseph DurbinPompeo faces pivotal vote To succeed in Syria, Democrats should not resist Trump policy Hannity, Kimmel, Farrow among Time's '100 Most Influential' MORE (D-Ill.) on Tuesday joined Chicago Mayor Rahm Emanuel (D) in calling for Rep. Jesse Jackson Jr. (D-Ill.) to explain to his constituents whether he will be able to continue serving in the House in 2013.

Durbin was asked whether he agreed with Emanuel who, on Monday, said Jackson Jr. should have a "conversation" with his constituents about his plans for the future. Jackson is reportedly negotiating a plea deal with federal prosecutors over allegations that he misused campaign contributions to redecorate his Washington, D.C. home. The federal probe of Jackson comes as he continues to receive treatment for severe bipolar disorder.

"It has reached that point and I have tried to be sympathetic and understanding because I believe that mental illness is in fact an illness," Durbin said, in an interview with WDWS 1400, a Champaign, Ill. radio station. "It can be treated and should be taken seriously and I stand behind those who are struggling with it but there are so many issues that are emerging here and he is a public figure, and there reaches a point where he has to square what is being said about him with the reality of his life and he has to step up and say more."

Jackson has been on a leave of absence from Congress since June to receive treatment for the mental disorder.

The deal that Jackson's attorney is reportedly negotiating with Justice Department officials includes the congressman repaying some of the campaign money he allegedly misused and resigning from Congress citing health reasons.

Jackson Jr.'s office has not responded to requests for comment on the negotiations.

On Tuesday, The Wall Street Journal reported that Jackson's wife, Chicago Alderman Sandi Jackson (D) is also under investigation by the FBI for possibly aiding in the misuse of campaign funds.

Just ahead of the 2012 election Jackson Jr. recorded a robocall to his constituents asking them to stick with him while he receives treatment for bipolar disorder, but did little else to campaign.

He easily won reelection, however, in his heavily Democratic district last Tuesday.