Mayor Bloomberg is fighting back against critics of his latest plan to overhaul the schools, marshaling a set of high-powered allies and pointing to the teachers union as the primary source of complaints.

Mr. Bloomberg appeared yesterday at a press conference in the Department of Education headquarters with dozens of supporters — representing churches, nonprofits, and city businesses — standing behind him. The mayor lashed out at the United Federation of Teachers, politicians, and newspapers, all of which he counted among the special interests he says are trying to block his changes to city schools.

“Number one, there’s the UFT. All they want to do is roll it back,” he said of the changes he has made so far in the schools. “There’s the political power of people who just want to pander when they come out and they find something wrong with everything. There are the newspapers that can never find anything good enough. They’re in favor of change but they’ve never yet in their whole publishing history seen a change that was good enough.”

Among those who signed the letter supporting the mayor’s efforts were the president of a local business group, the Partnership for New York City, Kathryn Wylde; the presidents of New York University, Columbia University, The New School, and the City University of New York; the president emeritus of the Museum of Modern Art, Agnes Gund; the chairman of the Association for a Better New York, a coalition of civic leaders, William Rudin; and several prominent church leaders, including the Rev. Floyd Flake, the Reverend Calvin Butts III, and the archbishop of the Church of God’s Children, Angelo Rosario, who said he is also the grandfather of 22 children who have attended public schools.

The letter, addressed to “New Yorkers,” states that the mayor’s “reforms make sense” and continues: “We can’t put special interests ahead of the interests of children.”

While talking about critics of his education plans, the mayor invoked the National Rifle Association.

“You always do have the problem of a very small group of people who are single-issue focused having a disproportionate percentage of power. That’s exactly the NRA,” he said. “Not very many people in this country want to put guns in the hands of criminals, and yet Congress is afraid to stand up against putting guns in the hands of criminals because of a small single-issue group. That’s what we’ve got to make sure doesn’t happen here.”

The president of the teachers union, Randi Weingarten, responded to the mayor’s comments by saying she wanted to “see the transcript first to see if he was just in a bad mood or if this is a change in direction from supporting teachers to criticizing them.”

The mayor described the people who had signed the letter of support as “independent” and “a group we can certainly turn to for a real, honest evaluation.”

On the list were leaders of some organizations that currently have contracts with the Department of Education, including Outward Bound and City Year, and the vice chairman for the Fund for Public Schools, which is chaired by Chancellor Joel Klein. Other signers included a group that is seeking city approval to open a charter school, Harlem RBI, and several organizations that attended a recent conference for groups interested in working with the Department of Education as partnership support organizations.

A Department of Education spokeswoman, Melody Meyer, declined to say how many of those on the list were applying for the partnership organization position because the proposals are currently under review.

When asked about the independence of the groups on the list that may be seeking contracts with the Department of Education or approval for charter schools, the mayor called the question “inappropriate.”

“They’re trying to make a difference,” he said. “I would argue that they’re people who rather than just want to talk about it are out there trying to actually do something.”

Yesterday the mayor also outlined what he said were improvements in the graduation rate and test scores to support his case for expanding changes to the school system, and he noted the city’s emergence as a finalist for the prestigious Broad Prize for Urban Education for the third year in a row.

“It’s going in the right direction, and we can all do it if we work together,” he said. “How can you look children in the eye and say ‘We could do more to help you, and we didn’t have the courage to do it’?”