Cracking the whip, the Delhi government today invoked the stringent ESMA declaring as illegal the nurses' stir which has severely affected functioning of state-run hospitals at a time when the city was grappling with rising cases of dengue and chikungunya.

"The LG has approved the government's proposal to invoke ESMA against agitating nurses," a top official said. The Essential Services Maintenance Act (ESMA) allows the government to declare a strike illegal in public interest. Around 20,000 nurses of various hospitals run by the Delhi and central governments went on an indefinite strike over issues relating to their salary and allowances.