A lawyer for a nonprofit group affiliated with New York City's mayor says it'll no longer cooperate with a state ethics probe because it has become a "blatantly political exercise."

An attorney for the Campaign for One New York sent a letter Friday to the Joint Commission on Public Ethics announcing the decision.

The commission for a year had been investigating whether the nonprofit engaged in prohibited lobbying.

The letter was obtained by The Associated Press. In it attorney Laurence Laufer says commission investigators are asking for records on subjects they have no jurisdiction to examine, including fundraising.

The commission's executive director says it has a legal obligation to look into whether the nonprofit's activities constitute lobbying.

The nonprofit was created to promote Democratic Mayor Bill de Blasio's agenda. It's shutting down.