Mayor Bill de Blasio on Tuesday declared his support for legislation that would limit contributions to political nonprofits — including his own Campaign for One New York.

The group took in $4.3 million, including from firms seeking lucrative government contracts or city approval for projects.

The mayor insisted that his support for the measure, which faces a City Council committee vote Wednesday and a vote in the full council Thursday, was not an acknowledgment that the donations his group accepted had been problematic.

“I’m only acknowledging that it became a big distraction, even though everything was done properly,” he told reporters.

The Campaign for One New York, which is closing, has been under investigation for months by federal and local law enforcement officials.