Dozens of school bus drivers won't get behind the wheel today,  protesting the Houston ISD's decision to hold classes on Good Friday.

"It's going to be interesting; it's going to be chaos."

The religious holiday is being used as a makeup day after classes were cancelled by winter storms earlier this year.  But Wretha Thomas with the bus drivers union tells our TV partner Local-2 the decision is not sitting well with some workers.

"HISD has over 80-percent of their employees are Christians.  And they have this day set aside for a makeup day."

The district says they have a backup plan in place and more than 100 drivers are ready to replace the protesters. 

But parents may not send their kids to school anyway.  Jonathon Saenz with Texas Values says some districts are demanding proof that children are attending religious services in order to get an excused absence:

"They will consider it an excused absence, but they want the school to first ask parents to provide documentation."

He tells our own Matt Patrick the state law is very clear on the matter.

"It does not say that the students have to show proof of attending an event.  It says that they're excused."

Bus drivers are holding a noon rally at MacGregor Park to protest the district's decision to hold classes.