What to Know United Teachers Los Angeles is delaying the start of a possible teachers strike until Monday.

Thursday was the original strike date publicly set by the union weeks ago, but the Los Angeles Unified School District has challenged that.

That legal challenge is still playing out in Los Angeles Superior Court.

Another bargaining round between Los Angeles Unified School District officials and teachers union leaders did not produce any new results Wednesday, raising the likelihood of a full walkout.

United Teachers Los Angeles earlier Wednesday moved its pending strike from Thursday to Monday in response to the district challenging that date in court, contending it was not given official 10-day notice, as state law requires, although the legal challenge is still playing out in Los Angeles Superior Court.

Union President Alex Caputo-Pearl reiterated that the strike would occur Monday unless the union sees a "serious" proposal by then. Union and district leaders met face-to-face at LAUSD headquarters for about five hours, but emerged from the negotiations still far apart on a number of key issues.

Caputo-Pearl told reporters he "did not see seriousness" from the district, and was also critical of the fact that Superintendent Austin Beutner was not present for the negotiations.

Beutner and school board President Monica Garcia were in Sacramento to meet with state leaders to seek more revenue for the district, according to a district official.

"We are working hard to avert a strike," Beutner said in a statement released Wednesday. "We are building support at the state level to find more resources to help our students and better support all who work in our schools."

Caputo-Pearl said another round of talks was scheduled for Friday at 9 a.m. Beutner and Garcia were expected to brief reporters at 5:30 p.m. The sides remain at odds over the size of a proposed raise, along with how much money should be spent to add support staff, reduce class sizes and other issues.

The LAUSD has offered teachers a 6 percent raise spread over the first two years of a three-year contract, while UTLA wants a 6.5 percent raise that would take effect all at once and a year sooner. UTLA also says it wants "fully staffed" schools with more nurses, librarians and counselors added to the payrolls, along with pledges to reduce class sizes.

On Monday, LAUSD raised its previous offer by $75 million to add more than 1,000 members staff to schools and help decrease class sizes, up from an initial offer of $30 million. Caputo-Pearl argued the offer would not make a significant impact and could actually end up raising class sizes.

He also said the offer was a spending plan which would only last one year. Caputo-Pearl also said the district raise offer for teachers would be contingent on cutting future health care benefits, which the union could not accept. Another disagreement between the two sides is over a reported $1.8 billion reserve the district has.

UTLA argues that the reserve could be tapped to pay for its demands, while Beutner has said the reserve has already been fully earmarked, including for the potential raises for teachers.

He has argued the UTLA demands will push the district into insolvency.

"There's no more than that, so the notion that we are hoarding reserves, the notion that more money exists somewhere else to give more to reduce class sizes at this time, is not accurate," Beutner said on Monday. "We are spending more than we have in service of our students."

Should a strike occur, it would be the first teacher walkout for LAUSD since 1989. As the second largest school district in the nation, it covers an area totaling 710 square miles and serves over 694,000 students at 1,322 schools, although 216 schools are independent charter schools, most of which are staffed with non-union teachers that would not be impacted by the strike.

The district says about 500,000 students and 1,100 schools will be impacted by the strike. About 80 percent of the district's students come from low-income households and qualify for a free or reduced-price lunch, and around 25 percent are learning English but the district says it intends to keep all of its schools open while it also continues to serve around 1 million meals each day.

The district also says it intends to attempt to keep some instruction going for students, as 400 substitutes have been hired for the task and 2,000 administrators with teaching credentials have been reassigned. However, with over 25,000 teachers expected to strike, the district is expected in many cases to do no more than supervise students during the day in auditoriums and other large spaces.

The district and union have been negotiating for nearly two years without coming close to a resolution, and UTLA's members have been working without a contract for over a year. They've already gone through mediation and a fact-finding session in recent months.

The fact finder's report was issued last month, and it sparked more verbal sparring between the two sides. On Monday, the union withdrew a demand to give teachers more control over standardized testing issues and budgets.

The union also removed a demand to have a voice when the district starts a new magnet program. And although the district came forward with its new proposal to add 1,000 positions, Caputo-Pearl said he was surprised LAUSD offered "so little" and that a strike was still likely.

UTLA also announced a separate strike at three charter schools is also in the works. The union represents teachers at three South Los Angeles charter schools operated by The Accelerated School, and said the strike would be the first at a charter school in the district.

The strike is set to begin on Tuesday after UTLA and the schools' management have failed to reach a contract agreement after 20 months of negotiating, UTLA said.

Leaders at The Accelerated School could not immediately be reached for comment.