Wisconsin Gov. Scott Walker’s broad challenge to government unions won’t be replicated in New York state anytime soon. The more relevant question is whether New York’s leading politicians will at least begin chipping away at some of the unions’ more egregious privileges — before the state sinks any further under the weight of their growing costs.

In the more than 40 years since the enactment of the Taylor Law, which mandated collective bargaining for all public sector employees in the Empire State, unions representing those workers have evolved into a virtual fourth branch of government here. Governors and legislators in both parties have granted the unions a de facto veto over structural changes in the Taylor Law framework — even over pension changes, which are technically a “prohibited” subject in contract negotiations.

For decades, as the bargaining table in New York tilted further in the unions’ direction, proposals to restore some management rights in the public interest have been doomed to die in the Legislature. Indeed, despite broad support from local elected officials in both parties, such proposals generally haven’t even been introduced.

But a few small cracks have begun appearing in the facade. Last week, Sen. John Flanagan (R-Suffolk), chairman of the Education Committee, introduced a bill modifying the “last in, first out” policy requiring that teacher layoffs occur in strict reverse-seniority order, regardless of classroom performance. LIFO is a cherished doctrine of public sector unionism, and not just among teachers.

Meanwhile, a small group of Assembly Republicans (members, to be sure, of Albany’s least potent minority) has introduced a bill repealing the Taylor Law’s so-called Triborough Amendment, which dates back to 1982.

Unique to New York, the amendment keeps all provisions of a labor contract in effect even after the contract has expired. “This mandate undermines the collective bargaining process and discourages those at the negotiating table from making givebacks or concessions, putting New York’s taxpayers at an extreme disadvantage,” the sponsors of the repeal bill note.

Triborough is especially valuable to teacher unions, whose members spend most of their careers receiving annual “step” increases in addition to negotiated raises in their base pay. When school districts seek concessions, unions can stonewall with the knowledge that their members will continue receiving pay hikes even after the contract expires.

The Triborough Amendment is also imposing an added cost on the state government. State worker contracts expire at the end of March, and Gov. Cuomo has said he will freeze pay for at least a year — yet his budget includes $140 million more in Triborough-mandated “step” increases for about 50,000 employees.

On top of that, the governor has budgeted $346 million to pay for unsettled contracts, including the costs of unsettled binding arbitration proceedings with the union representing corrections officers. Arbitration for public safety employees is another key union privilege that has tended to drive up salaries while minimizing management’s leverage to seek savings in contact talks.

Since Cuomo is unwilling to push for modification or repeal of the Triborough Amendment or compulsory arbitration even to help balance his own budget, it should come as no surprise that he avoided taking a stand on these issues as they affect local governments. Instead, he has punted proposed changes in costly labor mandates to a “redesign team,” whose “stakeholder” members include union representatives loudly opposed to any change.

As long as Cuomo remains timid when it comes to structural reforms, he and other elected officials will effectively be trying to tackle huge budget problems while wearing handcuffs. Employee compensation costs typically range from just over half of municipal budgets to nearly three-quarters of operating expenses for a typical school district. Pension fund contributions, in particular, are now a leading source of rising costs at every level of government, threatening to crowd out basic services.

Current collective bargaining rules rob government managers of the flexibility they need to cope with falling revenues while trying to maintain services. In the end, they often find themselves forced to resort to mass layoffs — a lose-lose proposition for both taxpayers and the workers who lose their jobs.

It’s pointless to blame the unions themselves for this situation. After all, they are only acting the way unions are supposed to act — relentlessly pursuing the interests of their members, period.

The real blame falls on the generations of elected officials who have abdicated their responsibility by creating and nurturing this system.

While the debate over public-sector collective bargaining is usually portrayed in partisan or ideological terms, left-of-center politicians were not always so enamored of unionism in government. President Franklin D. Roosevelt, a patron saint of organized labor in the private sector, famously opposed extending the same bargaining rights to public-sector employees.

One of the best descriptions of the corrosive impact of unions on accountability in government came from Frank Zeidler, the Socialist mayor of Milwaukee for a dozen years from 1948 to 1960, the period when Wisconsin mandated public-sector collective bargaining.

“The net effect has been to create what amounts to a two-chamber local government,” Zeidler later wrote. “One chamber is made up of elected representatives and chief executives . . . the traditional decision-making body for local government. The other chamber comprises the organized public employees who have gained official recognition to negotiate. The public business on wages and conditions of work, and therefore indirectly on policy, cannot be carried on without mutual agreement between these two chambers.”

Those words precisely describe the situation across New York today.

Cuomo has, at least, been willing to strongly advocate a local property tax cap in the face of strident union opposition. And Mayor Bloomberg is now belatedly pushing for pension changes the unions oppose.

But far more fundamental reforms are needed. Amid heated rhetoric about employee “rights,” the interests of taxpayers have been lost in the shuffle.