Updated 06/05/12 – 6:07 p.m.

CHICAGO (CBS) — Chicago Teachers Union president Karen Lewis met with more than 200 teachers and other union members Tuesday morning at Lane Tech High School, one day before the union takes a strike authorization vote.

As WBBM Newsradio’s Bernie Tafoya reports, Lewis said she expects teachers to overwhelmingly authorize a strike, if needed, when most of them vote on Wednesday. Teachers have three days to cast their ballots. If that’s not enough time, the voting period could be extended.

The ballot was delivered to all Chicago Public Schools this week, asking teachers a simple “yes or no” question: do you authorize a strike?

“People are ready to go,” CTU Vice President Jesse Sharkey said.

CBS 2’s Dana Kozlov reports approximately 25,000 CTU members are eligible to vote for a strike. State law requires 75 percent of them vote yes in order to legally authorize a strike. If not, a strike is not a legal option.

LISTEN: WBBM Newsradio’s Bernie Tafoya reports

Lewis said one of the complaints she has been hearing from members is they are upset that the Chicago Board of Education took away a planned 4 percent pay raise this year.

“When they took that raise, and then at the end of the year, there was a $700 million reserve, people felt very disrespected by that,” Lewis said. “We felt it was a political move to force us to strike earlier, so that the contract could be open; the longer school day could be imposed.”

But Lewis says the Teachers Union didn’t fall for that. She says teachers are thinking, and they plan.

Some parents said the vote is a must.

“I think it’s absolutely necessary,” said Matt Farmer, a board member with the parent group Raise Your Hand. “Here’s why: because, to date, the topics that the city, CPS, is willing to negotiate with teachers on have been very narrow.”

Michelle Beaver, with the 19th Ward Parents Organization, said she knows if teachers vote to authorize a strike, that doesn’t mean they will go on strike.

“No, it’s just giving them the option to, if they have to,” she said. “I’m definitely okay with that.”

But not everyone is.

In a radio ad paid for by the group “Education Reform Now,” listeners are urged to “sign” a text message petition against teachers taking a strike vote before an independent fact-finder releases a report this summer. That report could serve as the basis for a contract compromise.

Education Reform Now touts itself as a group supporting parent choice in education – and opposing the current public school bureaucracy.

The mayor continued to push for patience on Tuesday as well.

He made it clear he feels it would have been better if the CTU had waited for the independent fact-finding panel to complete its work.

“Teachers deserve a pay raise. We’ll work towards that. And the kids do not deserve a strike,” the mayor said. “And I think if everybody’s time and energy is focused on working with the independent third-party negotiator, or arbitrator, we will find that common ground to achieve both objectives.”

Tuesday afternoon, CPS Chief Executive Officer Jean-Claude Brizard also sent out a letter to teachers, urging them not to vote until that fact-finding report is released.

LISTEN: WBBM Newsradio Political Editor Craig Dellimore reports

Sharkey insisted the union doesn’t want a strike.

“What we want is a reasonable contract settlement,” he said.

But the union said CPS wants to put off the strike vote until after schools will be out and teachers will be off work for the summer by then, and not as likely to vote on a strike.

Furthermore, while the fact-finder’s report due out July 15 will address salary issues, Lewis says it will not settle everything in the teachers’ contract even if the teachers do agree to its provisions.

Salary issues are a paramount concern for the union. Brizard has claimed the teachers is seeking a 30 percent pay rise in their new contract, and that the school system cannot afford it.

Earlier reports said the union had proposed a 24 percent raise, while CPS had proposed a 2 percent raise. Brizard said previously that perhaps the number that will be agreed on will be somewhere in between, that those numbers may be “beginning places.”

State law requires that 75 percent of the Teachers Union’s total membership vote in favor of a strike in order to authorize a work stoppage.

Chicago teachers have not gone on strike since 1987. Back then, the teachers only needed a simple majority to authorize a strike. Now, they need 75 percent of membership to vote in favor of a strike in order to hold a walkout.