Public-private partnerships can leave subcontractors without financial guarantees or recourse when a private entity builds on public land, the sub's trade group argues in a letter to Engineering News Record.

"The American Subcontractors Association would like to raise your awareness about a concern that construction subcontractors and suppliers have with public-private partnerships (P3s)," the group wrote in the letter published on the magazine's website, enr.construction.com.

"Existing federal and state laws establishing payment assurances for subcontractors and suppliers may not apply to projects financed through P3s," the letter said.

Generally, mechanics liens don't apply to projects on public land, the ASA said, and payment bond requirements do not apply to private entities.  It gives subs the worst of both worlds, they argued, and "is problematic since subcontractors and suppliers extend large amounts of credit on construction projects"