PHOENIX (Reuters) - The Arizona Senate on Tuesday approved a measure to make gold and silver legal currency in the state, in a response to what backers said was a lack of confidence in the international monetary system.

Gold Bullion and coins from the American Precious Metals Exchange (APMEX) is seen in this picture taken in New York, September 15, 2011. REUTERS/Mike Segar

The legislation cleared the Republican-controlled Senate by an 18-10 vote after being approved by the state House earlier this month. It now goes to Republican Governor Jan Brewer, who has not indicated if she will sign it into law or veto it.

The bill calls for Arizona to make gold and silver coins and bullion legal tender beginning in mid-2014, joining existing U.S. currency issued by the federal government.

If signed into law, Arizona would become the second state in the nation to establish these precious metals as legal tender. Utah approved such legislation in 2011.

More than a dozen states have considered similar legislation in recent years, according to the National Conference of State Legislatures.

The use of gold and silver as currency would be strictly voluntary, with businesses left free to accept the precious metals as payment for goods and services as they choose.

State Senator Chester Crandell, a Republican and sponsor of the bill, said the ability to use gold and silver in everyday life in the state is still a “work in progress” and that more legislation was needed before it could be viable.

“This is the first step in getting it into the statute so we can build on it,” Crandell said at an earlier hearing on the bill.

But Democratic state Senator Steve Farley said the bill could create massive problems for businesses in the state and government officials trying to administer what would in effect be a dual monetary system.

“There’s no reason for us to do this,” Farley told lawmakers during the final vote on Tuesday. “This is another one of those things that gets national press for us - and not in a good way.”

He also pointed to the recent decline in the value of gold - which sank to $1,321.35 per ounce on April 16, its lowest price in more than two years - noting that “anybody who thinks gold or silver is a really safe place to put your money had better think again.”

The push to establish gold and silver as currency has become increasingly popular in the United States in recent years among some hardline fiscal conservatives, with the backing of groups including the Tea Party movement, American Principles Project and the Gold Standard Institute.

Keith Weiner, president of the Gold Standard Institute advocacy group and a supporter of the bill, said the legislation was needed to counter what he sees as insolvency in the global monetary system.

“The dollar system and all of the other derivative currencies, including the euro, are a recipe for worldwide bankruptcy,” Weiner told lawmakers at an earlier hearing, adding that a “sound and honest money system such as gold and silver” was needed to bring stability.