Just a month ago, a parent group created by the city’s schools chancellor, Joel Klein, boycotted his lobbying trip to Albany. Now, the same group is campaigning against one of Mr. Klein’s signature issues – charter schools.

Despite the growing rift, Mr. Klein said he has no plans to disband the Chancellor’s Parent Advisory Council, although he did say it wasn’t acting in the best interest of parents.

In a letter sent yesterday to the Assembly speaker, Sheldon Silver, and the Senate majority leader, Joseph Bruno, the council urged Albany to deny Mayor Bloomberg the authority to open more charter schools across the city.

The chairman of the council, Tim Johnson, charged that the schools – which are publicly funded but privately run – are draining resources from existing public schools and causing more overcrowding.

“All of his attention seems to be on this charter obsession, and I don’t get it, I really don’t get it,” Mr. Johnson said yesterday of Mr. Klein. He said parents feared that charter schools were “one step down the road” to vouchers and the privatization of the city’s schools.

New York City already has 47 charters, with another 13 slated to open in September. Mr. Klein has said charter schools are an essential part of overhauling the city’s school system.

The Bloomberg administration has been pushing Albany to adjust the 1998 state law that allowed for the creation of charters but limited the number of such schools to 100.The state has now met its cap.

About 12,000 – or roughly 1% – of the city’s 1.1 million public school children are enrolled in charter schools.

“When it comes to charter schools, it looks to us that their position is more politics than parent advocacy,” a spokesman for the Department of Education, David Cantor, said. “I don’t know how you can say that you really represent parents when you’re encouraging state lawmakers not to give thousands of parents in the city these opportunities.”

Mr. Cantor said thousands of families are on waiting lists to get their children into the city’s charter schools.

The council voted to send the letter after meeting with Mr. Klein last week to discuss their differences.

The charter debate flared up in recent weeks with two public schools protesting the education department’s attempts to move charter schools into existing public school spaces.

The schools – located in Harlem and on the Lower East Side – argue that the charters would put the squeeze on much-needed classroom space. The education department says those buildings are underutilized and that there is room enough for both schools.

Parents from New Explorations Into Science, Technology and Math, a school for gifted children, packed a council meeting last week to plead with Mr. Klein to open the proposed charter school in another building.

While Mr. Klein has made parent engagement a keystone of his sweeping education reforms, this is not the first time the council – which he created to represent the city’s 1,400 schools – hasn’t seen eye to eye with him.

In March, the rift over charters and other issues like class size prompted the council to boycott the education department’s annual visit to Albany. Instead, the group voted to go along with the United Federation of Teachers.

The charter issue is now at a crucial juncture in Albany as state lawmakers battle over whether to lift the cap.

Governor Pataki made an unsuccessful bid to raise the cap to 250 as part of last month’s budget negotiations. His proposal also would allow Mr. Klein to open limitless charters in the five boroughs. Both the Senate and the Assembly scrapped that proposal.

Spokesmen for Messrs. Bruno and Silver said yesterday that they had not seen the letter, but that the Legislature would revisit the charter issue after it worked out the budget.