Gov. Cuomo is framing his state budget proposal as an effort to end Albany’s ingrained habit of unsustainable and unaffordable spending. But when it comes to one important budget category, all Cuomo can do is ask for cuts.

The category in question is New York’s court system — one of the most expensive in the nation, on a per-capita basis. The $2.6 billion Judiciary budget has risen 73 percent in the last decade, a period in which all state operating costs rose 59 percent.

While Cuomo has ordered across-the-board cuts of 10 percent in state agency spending, Chief Judge Jonathan Lippman is seeking $84 million more for court operations next year. Including pension costs, adoption of Cuomo’s proposed budget bills would boost Judiciary spending by 5 percent, even while the total state budget is dropping.

Why would Cuomo let this happen? Because he has no choice.

As a separate branch of government, the Judiciary is uniquely entitled under the state Constitution to have its annual budget request forwarded by the governor directly to the Legislature, without changes.

The Legislature did reduce the Judiciary’s requested appropriation last year — but even after that cut, the courts are expected to spend 4 percent more in 2010-11 than they did the previous year.

The state’s judges jealously guard their independence — as they should. But in the past, they also have resisted fiscal restraint even when other government agencies were being pressed to sacrifice.

During the fiscal crisis of 1991, for example, then-Gov. Mario Cuomo’s attempts to reduce the judicial budget led to a major confrontation with then-Chief Judge Sol Wachtler. In the end, a compromise was struck — and the next two decades brought a significant expansion of the Judiciary budget.

The total state workforce has dropped in the last 20 years, but the Judiciary’s payroll has swelled — from about 14,000 full-time equivalent employees in 1990 to more than 18,000 as of 2010, according to figures from the state Comptroller’s Office.

Ironically, the judges themselves haven’t benefited much from the expansion of their budget: Unlike their staffs, they haven’t had a pay raise since 1999.

State Supreme Court justices are now paid $136,700, less than first-year lawyers at many big Manhattan firms. Federal district-court judges, meanwhile, earn $174,000.

After several years of wrangling with the Legislature, in and out of court, the judges won a victory last year when lawmakers agreed to create an independent commission to set judicial salaries. But the commission hasn’t been formed yet, and the pay hike may not come until 2012, at the earliest.

While Cuomo will have a fight on his hands in most other areas of the budget, the path to a common-sense compromise seems clear when it comes to the court system. The Legislature should signal its willingness to accelerate the work of the judicial pay commission and to deliver quickly on whatever raise it recommends.

State lawmakers should also take up the court-reorganization plan proposed several years ago by then-Chief Judge Judith Kaye. That plan, which requires a constitutional amendment to fully implement, could yield savings of $59 million a year — more than enough to offset the cost of a judicial pay hike.

Judge Lippman should return the favor by formally acknowledging that the state’s courts must be part of the drive to do more with less. The Judiciary should agree to find enough savings in its budget to pay for any judicial pay increase — and then some.

For example, a roll back of court staffing to late 1990s levels could save about $190 million in the next two years. The system might also accelerate its transition to electronic filing and digital recording of cases, and so reduce its dependence on well-paid court reporters (more than 500 of whom earn more than $100,000 a year).

The result could be a rare win for all concerned. You might even call it justice.