As Sen. Bill Perkins prepares to hold a hearing to, as he puts it, “look at the books of companies affiliated with charter schools” today, the pro-charter organization Education Reform Now has launched a new ad that features parents scolding the Harlem Democrat.

The ad has been added to the mix of spots already in rotation in the downstate market, and will be a “significant part” of the buy, according to a spokesman for the group.

Perkins is under fire from charter school advocates, who are shopping for a potential primary opponent to take him on this fall. They might be assisted by allies of Gov. David Paterson and Rep. Charlie Rangel, who aren’t pleased with the outspoken senator’s willingness to speak his mind about these embattled fellow Dems.

The senator, who holds Paterson’s old seat, has been widely speculated to be eyeing a potential primary challenge to Rangel, but he is so far keeping his powder dry. Perkins formally announced his re-election campaign last weekend.

charter school ad from Elizabeth Benjamin on Vimeo.