New York state’s newly proposed public campaign finance system has a flaw that could prove fatal if challenged in court, attorneys said Tuesday, provided that members of the state Legislature don’t first act to repeal the new elections scheme.

The lack of a severability clause—a provision that would allow parts of the new system to be severed and upheld in a legal challenge, while others are struck down—could leave the measure vulnerable to being overturned wholesale if a court finds one constitutional lapse.