The Arizona Supreme Court ruled Thursday that the Legislature can't cut cost-of-living increases promised to judges and state elected officials.

The court unanimously upheld a Superior Court judge's ruling in favor of retired judges who challenged the Legislature's 2011 decision to cut benefits increases for retirees in the state plan for judges and other elected officials.

The Legislature cut the cost-of-living increases after the judges' retirement system lost money in the Great Recession after gradually becoming underfunded in previous years.

Denying an appeal by state officials, the high court agreed the increases are part of a promised retirement benefit and are protected by the pension clause of the Arizona Constitution. That clause bars "diminishing or impairing" public retirement benefits.

Lawyers for the retired judges had argued that the clause protected both their retirement benefits and the increases to those benefits, while lawyers for the state argued that the protection only applied to benefits with increases calculated by current methods.

Arizona is not alone in grappling with the problem of underfunded public pensions. A proposed ballot initiative in California would allow cities to renegotiate public workers' future pension and retirement benefits. Oregon's Legislature passed a law similar to what Arizona passed in 2011 that cuts future cost-of-living adjustments.