Opposition is growing to an Arizona bill which opponents say would allow businesses and individuals to discriminate against gays.

The measure, which states that individuals and businesses can refuse service based on their religious beliefs, cleared the Senate on Wednesday and the House the following day. Calling the measure “controversial,” Republican Governor Jan Brewer said she will decide whether to sign the bill this week.

Three Republican state senators who voted for the bill – Senators Bob Worsley, Adam Driggs and Steve Pierce – are now urging Brewer to veto the legislation.

“I screwed up,” Pierce told Capitol Media Services of his vote. “I'm trying to make it right.”

The Arizona Chamber of Commerce and Industry also came out against the measure, saying it fears such a law would hurt the state's tourism industry.

In fact, actor George Takei has already called for a boycott of Arizona if the bill becomes law.

(Related: George Takei: Boycott Arizona if Gov. Jan Brewer signs “turn away the gays” bill.)

Over the weekend, U.S. Senator Jeff Flake, also a Republican, tweeted his opposition to the bill.

“I hope Governor Brewer vetoes SB 1062,” he messaged.

At least two Arizona mayors have also spoken out against the bill.

Tucson Mayor Jonathan Rothschild wrote in an open letter that the measure would “take our state backwards to a time when discrimination was the norm.”

“I ask our governor in the strongest possible terms to veto this legislation, and I urge Tucsonans to contact her with that request as well,” Rothschild wrote.

Phoenix Mayor Greg Stanton also criticized the measure in comments to gay weekly The Advocate.

Roughly 300 people rallied against the bill outside the state capitol on Friday.

(Related: Hundreds rally against Arizona bill allowing businesses to discriminate against gays.)