Making good their threat, more than 70,000 civic employees began their indefinite strike on Monday night after talks with the civic administration over pay revision failed.
Essential services like garbage collection, health, water supply and the fire brigade will be affected, though the civic administration is working on keeping these services going.
The strike has been called by the Sharad Rao-led Municipal Mazdoor Union (MMU) after the civic administration refused to meet their demands of a pay revision as per the sixth pay commission recommendations.
Municipal commissioner Subodh Kumar called the strike illegal and said the BMC was prepared to deal with it. He also said if any services were disrupted, then the Essential Services Maintenance act would be invoked against protesters. The state government, too, declared the strike illegal and warned the unions of stern action.