Hong Kong is bracing for the largest citywide strike in decades on Monday, after about 14,000 people from 20 sectors vowed to join the industrial action against the now-abandoned extradition bill, first called for by staff unions of transport operators and social workers.

But business leaders have warned the employees of a government and an economic backlash.

Protesters were set to launch the strike in eight districts — Admiralty, Mong Kok, Sha Tin, Tai Po, Tsuen Wan, Wong Tai Sin, Tuen Mun and around the theme park Hong Kong Disneyland Resort.

Police said on Saturday they had received applications for rallies from six districts and issued no-objection letters for Admiralty, Wong Tai Sin and Tuen Mun.

Hongkongers have always put work as a priority. But now some people are defying that and supporting the five demands of the anti-extradition movement, including a full withdrawal of the now-abandoned bill and an independent investigation into police’s use of force on the demonstrators.

On Saturday, nine people, many of them wearing a mask, said in a press conference they had gathered 14,000 locals from more than 20 sectors, and some had already applied for leave to take part in the strike.

A spokesman for the strike’s organising committee who gave his name only as Chan, said they were left with no option but to go on strike as the government “did not pay heed to people’s demands”.

“Various sectors have expressed their views in most peaceful ways. But, the government did not listen to them,” he said.

“A lot of protesters were attacked with violence, and persecuted by a tyranny ... When the society has become like this, we need to paralyse it temporarily to force the government to face the problems.”

At the same event, a person from the insurance industry who identified himself as Poon, said he hoped the employers would not punish their employees for taking part in the strike.

“Some frontline insurers specialise on clients from mainland China, who trust Hong Kong’s legal system. But the government here has repeatedly challenged our rule of law. I hope the insurers stop meeting their clients for a day and go on strike,” he said.

With workers from sectors – such as finance, civil service, education and arts and culture – expected to join the strike, the city, which always prided itself for being efficient and convenient, could see large-scale disruptions on Monday.