PHOENIX - State lawmakers return to the Capitol today in hopes of quickly approving a ballot measure aimed at the ability of unions to organize.

The proposal seeks to add a provision to the Arizona Constitution guaranteeing that any election by workers to decide whether to form a union must be conducted by secret ballot.

House and Senate committees are scheduled to debate the measure in hearings this afternoon, with debate by both chambers Tuesday and final roll-call votes Wednesday. Gov. Jan Brewer supports the change.

It is being pushed as a pre-emptive strike against the possibility the Democratic-controlled Congress will pass a "card check" law.

Current labor law requires those who seek to unionize to get the signatures of a majority of affected workers. But all that does is authorize an election, which the union or the employer could demand be done by secret ballot.

A card check law would require that the union be formed simply with the written consent of a majority of the workers.

Clint Bolick of the Goldwater Institute admitted that the purpose of the amendment, which would go on the November ballot as Proposition 113, is to try to keep unions out of some businesses.

"Card check, in my view, would dramatically increase private sector unionization in places like hamburger restaurants and other small business establishments where unionization could absolutely wreck the businesses," he said. Bolick said an open system could result in coercion by union organizers who know who does and does not want to organize.

Unions are the ones lobbying for the change in U.S. law, he said.

It's not clear what would happen if Congress approves card check and voters adopt the amendment. Federal law generally pre-empts any state laws or constitutional amendments. But Bolick, an attorney, said it could be argued states are entitled to provide a protected First Amendment right for their residents above and beyond federal law.

Even if that isn't the case, Bolick said public employees and agricultural workers are not subject to the National Labor Relations Act, meaning their elections would be subject to the secret ballot rule regardless of federal law.

The GOP-controlled Legislature voted last year to put the issue on the November ballot. But a judge knocked it off because of its wording.

The idea of a special legislative session to fix that wording mistake - and to alter the Arizona Constitution for something that is not yet federal law - drew derision from legislative Democrats. Rep. Kyrsten Sinema, D-Phoenix, called it "a complete and total waste of taxpayer dollars."

She estimated it costs taxpayers $10,000 a day to have lawmakers in session. About half of that is the allowance lawmakers will get for being at the Capitol; the balance is staffing and even the cost of making copies of the proposal.

The timing of the session is designed to meet a deadline to put the proposal on the Nov. 2 ballot. The state constitution can't be amended without voter approval.