Lil Durk is facing a legal slugfest, with the feds claiming he's the mastermind behind a murder-for-hire plot ... and his attorneys are convinced it's a classic example of prosecutors grasping at straws with some street-savvy rap lyrics because they don't have a real case against the rap star.

The Chicago rapper's attorneys -- Drew Findling, Marissa Goldberg, Jonathan Brayman, and Christy O'Connor of The Findling Law Firm -- tell TMZ Hip Hop ... "When you see an artist’s rap lyrics quoted as 'evidence' against them, it is a glaring indication that there is no real evidence against that person."

According to the feds, Durk detailed the steps that led up to the August 2022 murder of rival Quando Rondo's cousin Saviay'a Robinson on Babyface Ray's song "Wonderful Wayne & Jackie Boy" when he rapped ... "Told me they got an addy (gooo) / Got location (gooo) Green light (go, go, go, go, go) / Look on the news and see your son, You screamin’, 'No, no' (p***y!!!)"

The song was released in December of that year, several months after the murder -- but Durk's lawyers say the claim there's a connection to the actual murder lacks merit.

They continue ... "The claims in the indictment against Mr. Banks are false and lacking in the most basic due diligence. The real truth is that Durk Banks is a Grammy Award-winning artist, a dedicated father, and a loving husband."

"Mr. Banks has been intensely committed to giving back to the Chicago community he loves through his Neighborhood Heroes Foundation and has put on more than a dozen charitable events over the last few years.

"He is looking forward to fighting against these false allegations in court."

Last month, Chicago Mayor Brandon Johnson stood tall and arguably seemed to even defend Durk after citizens were calling for the rapper to be canceled.

The same scenario also divided a pair of local mayors who received donations, but Durk's team isn't rattled.