Bronx Borough President Ruben Diaz refused to sign off on The Related Companies’ proposal to transform the borough’s largest indoor public space into a shopping mall.

He did the right thing.

The Bloomberg administration and its chosen developers expect communities to give carte blanche to projects even when they include massive chunks of prime public real estate and hand over considerable taxpayer subsidies to private companies. And they expect officials like Diaz to sign on the dotted line before negotiating Community Benefits agreements.

Adolfo Carrion, Diaz’s predecessor, went along, but with this action Diaz has set a different tone early in his new administration, as we urged him to do in a July editorial.

The borough president’s vote is advisory and the City Planning Commission, the majority of whom are mayoral appointees, is virtually certain to ignore it. But Related’s proposal will then head to the City Council.

While the Council rarely bucks the mayor on development issues, Diaz’s move puts pressure on the borough’s Council delegation, especially Council Members Maria Baez, whose district the facility is in, and Oliver Koppell, who has taken a keen interest in the Armory even though it’s just outside his district.

If the Bronx delegation votes “no,” then Council members from other boroughs will almost certainly defer to its decision.

The borough president did not act in a vacuum. He’s had wind at his back. The Northwest Bronx Community and Clergy Coalition has, for more than 10 years, organized residents, and held dozens of meetings and rallies with elected officials, including Carrion when he was in the City Council. And over the last few years, The Kingsbridge Armory Redevelopment Alliance (KARA), an umbrella organization of local groups, institutions, and unions led by the Northwest Bronx Community and Clergy Coalition, has laid out some core principles for redeveloping the Armory, chief among them a requirement that retailers pay their workers a living wage.

It’s the kind of thing that officials nominally support, but in the next breath mutter about its political infeasiblity, sort of like the way many centrist Congressional Democrats talk about the dimming prospects of the eminently reasonable yet controversial “public option” in the health care reform package. But KARA’s persistence has paid off and has pushed the living wage and other key issues to the center of the negotiating table, should Related decide to sit down at it.

If they don’t, we urge Council Members Baez, Koppell, and their 51 colleagues to vote no on Related’s proposal. Related and the city will bluster about how the Armory will then remain vacant for decades. But they will not walk away from a project this large and lucrative.

Meanwhile, we congratulate Borough President Diaz for having the courage to send a clear message to Related and other firms wishing to develop in the Bronx: the Bronx is open for business but it is no longer going to be taken to the cleaners.