The state’s largest teachers union has taken to the airwaves to blast Gov. Dannel P. Malloy’s plans to redirect more of the $2.1 billion in state education aid to the state’s most impoverished communities.

“What does it take to secure the future of Connecticut?” the 30-second television advertisement released Tuesday begins. “It takes investment in our public schools and a state budget that works for all of us – especially our children. But that’s being threatened by a plan that would divide our local public schools into winners and losers.”

The Connecticut Education Association plans to spend $100,000 to air the advertisement over the next two weeks on stations throughout the state.

The union takes issue with the governor’s proposal, which rejects the long-standing practice at the state Capitol of shielding individual cities and towns from state cuts to education aid.

“Protect funding for public schools in every community. Every, single, one,” the 30-second ad demands.

Malloy, a Democrat, has said that protecting towns from education funding cuts as their school enrollment shrank or their taxable property increased has disproportionately impacted the state’s most impoverished communities, where enrollment has grown over the years.

“That idea that we held communities harmless while they were shrinking meant that we didn’t fund schools that were growing,” Malloy told reporters last week in New Britain while announcing the changes he proposes to education aid.

The governor tried to appeal to suburban legislators during his budget address last week to help out struggling cities.

“We are a small state, and our towns are interconnected,” Malloy said. “Growth in Hartford means growth in Bloomfield and Windsor. More jobs in Waterbury means more jobs in Cheshire and Beacon Falls… We can rise together, or we can fall together.”

Malloy’s proposed budget would increase state education grants to 52 cities and towns with struggling schools by about $230 million. To pay for that he would drastically cut education funding to dozens of better-off towns, eliminating all funding for Greenwich, the state’s wealthiest community. (See how your town fares under Malloy’s proposal here.)

However, in many of the impoverished districts education aid increases he proposes would be wiped out by another one of his proposals, which would send municipalities a bill to cover one-third of the pension costs of their teachers.

For example, Hartford would get $12.2 million more in education grants under the governor’s plan, but the city would have to pick up $17.1 million in teacher pension costs that the state now covers.

The governor does propose allowing municipalities to levy a new tax on the property of hospitals. In Hartford, that tax could generate $57.1 million a year in new revenue for the city, though it would not be required to be spent on local schools. (See the bottom line for your town in the governor’s budget here.)

“We are all in this together,” said CEA Executive Director Mark Waxenberg when releasing the ad. “We have a lot of schools in need, but you don’t lift the boats of the poor by poking holes in the boats of the middle class. Legislators must find a solution that protects funding for every public school.”

Leaders of the state organizations that represent school boards, superintendents, school business officials and principals held a press conference last week to also blast the governor’s budget that cuts state education support for municipalities by $364 million.

“We have a pretty draconian system here,” said Dave Lenihan, of the Connecticut Association of School Business Officials.

Pressure to overhaul how schools are funded follows a superior court judge ruling last summer that the state is spending enough on education overall, but where that funding is going is irrational and unconstitutional.

“Too little money is chasing too many needs,” Hartford Superior Court Judge Thomas Moukawsher wrote in September, outlining huge disparities in achievement and spending between rich and poor towns. “If the egregious gaps between rich and poor school districts in this state don’t require more overall state spending, they at least cry out for coherently calibrated state spending” that factors in “the special circumstances of the state’s poorest communities.”