About 4,000 janitors who clean Twin Cities office buildings say they will go on a 24-hour strike Wednesday after negotiations stalled with the cleaning subcontractors who employ them.

Members of Local 26 of the Service Employees International Union voted Jan. 23 to authorize the strike. The janitors' last three-year contract expired Dec. 31, and talks for a new deal began in October.

It will be the first strike by subcontracted union janitors in the Twin Cities in decades, according to a statement from the union.

Local 26 represents janitors for cleaning companies who in turn have contracts with office building owners. Most of its janitors work in downtown Minneapolis and St. Paul, but some are in office buildings scattered around the seven-county metro area. The key cleaning companies involved are ABM Janitorial Services, Marsden Building Maintenance, ABLE Building Maintenance and Harvard Maintenance.

Full-time janitors make $14.62 an hour; part-timers make $11 to $13 an hour. The union has asked for immediate wage increases of $1 an hour across the board, and has proposed raising part-timers' hourly pay to $15 an hour by the end of a new three-year contract. Local 26 also wants workers to have more sick days.

John Nesse, a lawyer in St. Paul who is negotiating for the cleaning companies, said the janitors already receive "an industry-leading wage and benefits package that is significantly above our metro average," and their wage proposal has not changed in more than three months of negotiations.

Nesse said the companies offered in January to raise all full-time workers' pay above $15 per hour over three years -- but not part-time employees.

Brahim Kone, a janitor in St. Paul since 2001 who cleans a Department of Human Services building, said three years is too long to wait, given that the janitors clean buildings for very wealthy companies, and he believes part-time workers should be paid the same hourly wage as full-time workers.

"We want it now, and we also want to include the part-time," said Kone, a leader on the union bargaining team. "They're doing the same thing we're doing."

Also, the workload for janitors in office buildings, he said, is too much and unhealthy for workers and their families.

"We are fighting for our own families, but we also want our fight to show others that you don't have to accept the status quo," he said. "Our state and economy are not working for everyone."

After Wednesday's strike, the union will look at what to do next, Kone said.

"The employers respect the union's right to strike," Nesse said. "At the same time, we already have a bargaining session scheduled for February 22 and we're looking forward to getting back to negotiations."

Adam Belz • 612-673-4405 Twitter: @adambelz