BOSTON (AP) — A union representing striking teachers will be Grant Prestonfined an additional $50,000 a day if the strike continues next week, a Massachusetts judge ruled Friday, according to The Boston Globe.

Public schools in Newton have been closed for six days since the strike began last week. The Newton Teachers Association has so far been fined $375,000 by Middlesex Superior Court Judge Christopher Barry-Smith.

The judge imposed a smaller fine increase than in his previous ruling, when he ordered the fine be doubled each day. He said he didn’t want to undermine negotiations.

The judge had earlier issued a contempt order against the union for breaking a state law that bans public employees from striking.

The district educates nearly 12,000 students across more than 20 schools.

The Newton School Committee said in a message to parents that it had been making progress earlier in the week, but negotiations had faltered around midday Thursday. It said agreeing to the union’s demands would require it to lay off 60 employees within a year and another 60 within five years.

The committee said the district was proposing to spend an extra $45 million over the next four years compared to the union’s proposal of an extra $100 million.

“We know how hard this is on our families and students,” the committee said, adding that it was “fully committed to a resolution and return of our students and staff to the classroom as soon as possible.”

The negotiations have been going on for a year, the Globe reported. The union is seeking living wages for all employees, increased paid family leave time and a guarantee that social workers will be placed in every elementary and middle school.