Conservative activist Eric O’Keefe has a message for the Wisconsin prosecutors who have targeted him and dozens of conservative groups in a politically charged John Doe investigation: Drop the probe now or become defendants in a federal civil rights lawsuit.

O’Keefe, director of the Wisconsin Club for Growth, a limited government advocacy organization targeted for alleged illegal “coordination” with Gov. Scott Walker’s campaign during the state’s recall elections, said in a statement that the investigation is “political payback by elected prosecutors against conservative activists for their political successes in Wisconsin.”

“They are violating the constitutional rights of private citizens and must be held accountable,” O’Keefe said in the statement released Wednesday.

O’Keefe’s attorney, David B.Rivkin has sent a letter to prosecutors stating the nearly two-year John Doe investigation, conducted with a court-ordered gag order in place, has no basis in Wisconsin law and that it violates O’Keefe’s First Amendment rights to freedom of speech and association.

“I am confident that any federal court that reviews the facts will see your investigation for what it is, put a stop to it, and hold you publicly accountable,” the letter states.

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