With its teachers union continuing to withhold support, Glendale Unified faces the worst-case scenario of having to overnight its 70-page application for federal Race to the Top funds on Monday.

The grant application for the highly competitive pot of federal money requires the union to sign off on it, but Glendale Teachers Assn. is withholding its support because district officials have refused to commit to no layoffs next school year.

“We have rejected their counter offer,” said union President Tami Carlson. “We really feel the most important thing is the teacher in the classroom.”

As of Friday morning, Carlson had not signed the grant application, pushing the district ever closer to its deadline for turning it in to officials in Washington D.C.: 5 p.m. Tuesday, Eastern Standard Time.

“We were so hopeful that [Carlson] would come in and sign it before [Monday],” said Maria Gandera, assistant superintendent of human resources.

Following a round of negotiations last week, district officials and the union's bargaining team exchanged proposals and counter proposals.

A day later, the district agreed to maintain current health benefits for teachers and possibly remove five unpaid furlough days from the books in 2013-14.

But there was still one hold-up for the teachers union: district officials could not promise they wouldn't lay off teachers next school year, which could result in increased class sizes at the elementary level where students could be taught at a ratio of 30 students to one teacher.

But increased class sizes and teacher layoffs cannot be avoided, even with the Race to the Top grant — which could bring in $40 million, which would be spent in $10-million increments over four years, Gandera said.

While the Race to the Top grant money cannot be used to directly fund full-time teachers, it would be available for a broad range of programs and could be used to pay for in-classroom teacher intervention specialists.

Some detractors are also worried about how the district will continue to pay for the extra staff or programs after the federal grant money is spent.

“The [Race to the Top] grant is not going to be able to prevent us from increasing class size. We have a structural deficit of over $15 million a year. The grant would only give us up to $10 million a year,” Gandera said. “You do the math.”

There had been some pushback from the union over a grant provision that student test scores be included in teacher job evaluations. But that no longer appears to be the main issue, taking a back seat to more traditional battleground issues between the union and district.

Carlson said keeping teachers in the classroom and maintaining their healthcare benefits were the union's top priorities.

“Our members are speaking out pretty loudly and clearly that they don't want us to sign off on Race to the Top at all,” Carlson said. “If we can keep teachers in the classroom and maintain affordable healthcare for our teachers, the benefit of our students will outweigh the additional workload.”

On Friday, Gandera was clinging to the hope that Carlson would sign the grant application.

“Call me an optimist until the clock stops ticking,” she said.

Follow Kelly on Twitter @kellymcorrigan.