As public advocate, Bill de Blasio presented reports about how to improve the process through which schools are awarded space inside city-owned buildings. In 2011, de Blasio presented reforms to the co-location process, which has benefitted charter schools under Bloomberg.

Next week, thousands of parents will flood the Brooklyn Bridge to rally in support of the charter schools that their children attend. It’s an aggressive — and divisive — approach meant to send a message to Democrat and mayoral frontronner Bill de Blasio, who says he wants to slow the growth of charter schools and charge rent to the ones operating in city-owned buildings.

But a smaller group of school leaders and well-heeled charter backers are also taking a quieter approach in a hopeful attempt to seek influence with the Democratic mayoral nominee. Faced with increasing odds that de Blasio will be the next mayor — and the understanding that charter school parents are unlikely to support Republican Joe Lhota — they’re lining his pockets with campaign donations.

Some also attended a fundraiser Thursday to try to influence the likely mayor on education policy, which is being organized in part by Craig Johnson, a former Democratic state senator who now chairs the Democrats for Education Reform political action committee.

“I think it’s an opportunity for us to begin a dialogue around all the issues affecting kids, including universal pre-kindergarten, co-location, and all those issues,” said Ian Rowe, CEO of Public Prep, a network that operates four charter schools in the city.

Rowe was among the charter school supporters at the de Blasio fundraiser. Organizer Johnson, who worked with de Blasio on John Edwards’ 2004 presidential campaign, is among the names listed atop a fundraising invitation to the event, hosted by Martin Scheinman, a lawyer and contract arbitrator.

Other supporters, such as Public Prep chairman Bryan Lawrence, already opened their wallets to de Blasio at Johnson’s request. The reluctant embrace comes despite ongoing suspicions that de Blasio’s plans for education could hurt the charter sector.

“He says he wants to make the city better,” said Lawrence, who said he donated $4,950 to de Blasio, the maximum allowed for individuals under the city’s campaign finance laws. “And if he’s elected, we’re looking forward to working with him on how to do that.”

Lawrence said the donation isn’t a signal that de Blasio had earned his vote just yet. Last month, Lawrence gave $2,500 to Lhota’s campaign, and he said he is eager to learn more about both candidates’ education plans.

“I’m looking forward to seeing how both of them approach improving the public school system,” Lawrence said.

Paul Appelbaum, who along with Lawrence sits on the board of Families for Excellent Schools, which is organizing the Brooklyn Bridge march, contributed $2,500 to de Blasio, according to FES Executive Director Jeremiah Kittredge.

Despite their wary relationship with de Blasio, the charter sector is even more reluctant to support Lhota, whose education agenda maps more closely to their own. Lhota has pledged to double New York City’s charter school sector and continue to allow schools to operate in city-owned buildings rent-free. In contrast, de Blasio offered more details this week about the sliding scale he’d employ to charge rent to charter schools that have raised large sums of private money.

“Bill de Blasio is no friend to the education reform movement,” said a Lhota spokeswoman, Jessica Proud.. “He wants to obliterate charter schools despite their enormous success in educating our children.”

The de Blasio campaign declined to comment.

But charter school leaders said they see areas of agreement with de Blasio on education. Rowe pointed to de Blasio’s plan to expand early childhood access, which includes a tax on the wealthy to fund full-day universal pre-kindergarten. Rowe said he supports the plan, but added that de Blasio must embrace changing state law to allow charter schools to serve these students.

“Quality pre-kindergarten is one of the most important legislative initiatives, in particular for kids from the communities we serve,” Rowe said.

De Blasio has said he does not believe charter schools should be allowed to operate pre-K programs.

Some charter school advocates believe they can convince de Blasio to change his mind on that issue and others. And some also say participating in a massive rally that could end up attacking de Blasio is not the way to do it.

“All of my parents voted for de Blasio,” said Rafiq Kalam Id-Din, principal of Teaching Firms of America Professional Preparatory School in Bedford-Stuyvesant, explaining why his school would not attend the rally. “How could I tell my parents to then turn around and protest the person you just voted for mayor?”

But Kalam Id-Din said he was still troubled with de Blasio’s statements this week about charging rent to charter schools. To him, they represented a direct contradiction to de Blasio’s larger platform to address the city’s socioeconomic inequities.

“You’re going to tax the people who are trying to serve our most at risk students?” Kalam Id-Din said. “That to me is just perverse.”

Here’s the invitation for tonight’s de Blasio fundraiser, including a list of donors: