The Attorney General's office provided the House Speaker with an opinion on the Governor's authority to implement furloughs for state workers. Here is the letter from February 17, 2009. In summary, while the law is silent on the term furlough, it was the AG's opinion that the Governor would be unable to furlough without negotiating the terms of the furlough with the union.
The Attorney General's office revised their response on Friday. In summary, upon further review, the AG's opinion is that because furlough is a temporary reduction of hours, in this case due to economic reasons, the Governor is able to furlough without mandatory negotiation. Here is the letter from May 29, 2009.
Yesterday, Governor Lingle announced a plan to furlough certain state workers 3 days per month from July 1, 2009 for two years. The savings of $688 million will help to close the budget shortfall over the next biennium.