Dan Janison Melville. N.Y. Tuesday January 26, 2010. Daniel Janison,

Dan Janison has been a reporter at Newsday since 1997.

The latest public clash between Gov. Andrew M. Cuomo and Mayor Bill de Blasio reveals the separate -- and often competing -- labor alliances of New York's best-known elected Democrats.

De Blasio has been pushing in Albany to change a state tax-break program, due to expire this month, in a way that would get developers to build more "affordable" housing.

As part of that proposal, de Blasio seeks to assure building service workers of a proper wage level in the completed projects. The relevant union, 32BJ-SEIU, has close ties with the mayor, most certainly on this issue.

Enter the Cuomo-friendly trade and construction unions. Counter to de Blasio's plan, they demand a prevailing-wage guarantee in projects to be built with the tax breaks under this program, known as 421-a.

Gary LaBarbera, president of the Building and Construction Trades Council of Greater New York, publicly praises Cuomo for backing this drive. LaBarbera, a longtime Long Islander, is among those involved in the campaign against de Blasio's proposal by the group called Up4NYC.

Early in Cuomo's first term, LaBarbera was a key member of the since-disbanded Committee to Save New York. Through it, well-heeled interests funded ads in support of Cuomo's governmental agenda, geared at offsetting resistance from public-employee unions.

The current fight over 421-a has produced a rich lode of irony and role-reversal as Cuomo -- once again -- takes the lead in slapping down a key item on de Blasio's legislative agenda.

advertisement | advertise on newsday

For one thing, de Blasio, a self-styled national progressive leader, calls the trade unions' prevailing-wage demands detrimental to achieving his housing construction goals. This led Richard Trumka, the national AFL-CIO president, to call the mayor's 421-a revisions "disappointing."

The mayor's stance also puts him on the same page as the Real Estate Board of New York -- which isn't exactly a left-wing front group. Deputy Mayor Alicia Glen this week said that requiring union pay rates could mean thousands of below-market units won't be created.

On the opposing side, Cuomo -- whose campaign contributions from major real estate figures are unsurpassed in New York -- has attacked the mayor's plan as "a sweetheart deal" for big developers.

From the Cuomo camp these days also come talking points familiar to de Blasio about the need to correct income inequality and help working families.

As all the players know, this tax-break program factors in pending indictments against two lawmakers recently ousted from leadership posts, former Assembly Speaker Sheldon Silver (D-Manhattan) and ex-Senate Majority Leader Dean Skelos (R-Rockville Centre).

@Newsday

Both cases, in which the defendants have pleaded not guilty, partially involve their allegedly cozy dealings with a leading real estate contributor, Glenwood Management, around the time 421-a was coming up for renewal in 2011.

An agreement on extending 421-a seems increasingly difficult as the legislative houses look to adjourn by the middle of the month.

Just Tuesday came two thrusts in opposing directions -- Assembly Speaker Carl Heastie (D-Bronx) saying his conference supports a prevailing-wage provision, and the state Business Council warning against it. The clock, meanwhile, ticks down.