PETA is looking to tap Stormy Daniels for its next campaign ... promising the project will take a major jab at Donald Trump, TMZ has learned.
In a letter sent to the adult film actress -- obtained by TMZ -- PETA invites SD to collaborate on its next PSA, which rails against horse racing.
The campaign is set to release ahead of the Belmont Stakes and references Stormy's past sex confession involving the 45th prez .