SACRAMENTO ? With Democratic legislative leaders fuming, Gov. Arnold Schwarzenegger has shut down construction on a new death penalty chamber at San Quentin Prison.

The order came a little more than a week after lawmakers were first informed at a legislative hearing that the California Department of Corrections and Rehabilitation had embarked on its own to build the new quarters where it ultimately hopes to administer lethal injections to condemned inmates.

California executions had been carried out in San Quentin’s 69-year-old gas chamber.

At the April 12 hearing, corrections officials said they figured that the new death chamber would cost less than $400,000 and thereby not require legislative approval.

Cost overruns, however, pushed the price tag on the new death chamber above the $400,000 “minimum capital outlay” threshold, Corrections Secretary Jim Tilton told reporters in a conference call Friday. As a result, it now requires approval by the Legislature.

Added costs for special repairs related to the roof, electrical wiring, medical equipment and a new fire alarm system elevated the project’s total to $725,000, making it a “major capital outlay.”

“As soon as we figured this out, the governor ordered that the project be stopped,” Corrections Undersecretary Stephen Kessler said on the conference call.

U.S. District Judge Jeremy Fogel of San Jose halted the state’s lethal injection process Dec. 15, declaring it unconstitutional in part because of the dim lighting and crowded conditions in the San Quentin gas chamber.