The China Electronics Technology Group claimed that the engineer who opposed non-voluntary overtime work on Tomb-sweeping Day and the company he served are neither an official employee, nor the group's affiliated unit, and it reserves the right to take legal action over any rumors circulating online, as reported by people.cn on Wednesday.

That day, several WeChat screenshots containing an engineer's sharp words opposing non-voluntary overtime work on Tomb-sweeping Day, which was on Wednesday, went viral online, triggering a heated public discussion.

The screenshots read that the company, in Chengdu in the southwest province of Sichuan, needed two workers on duty on Tomb-sweeping Day, and published the notice in a group chat. It then appointed two workers to take the job without asking their permission.

One of the two workers, surnamed Chen, opposed the company's decision in strong terms, and pointed out the recent unreasonable overtime working schedule from 8 am to 11 pm, with his resistance being supported by his colleagues in the group chat.

On Wednesday, Sichuan Guancha, a new media outlet of Sichuan Radio and Television, reported that Chen has quit the company voluntarily after the dispute was exposed online. The company has not commented on the affair.

The province's Federation of Trade Unions said in an interview published in Workers' Daily on Wednesday that it is now cooperating with the Chengdu trade unions federation to intervene, and will take measures to protect workers' rights after conducting a thorough investigation.

The provincial federation said that it will also urge the company involved in the dispute to coordinate and listen to its workers' real needs to make sure it develops good working relations. The federation hopes that the online aspect of the dispute will not damage the worker's privacy.

Yao Junchang, co-founder of the Beijing Weiheng Law Office, said that the company should ask its workers' permission for overtime work and should pay them the overtime rate.

Yao said that under the "eight hour work system", employers should not ask employees to work overtime for three hours per day and 36 hours per month when necessary to lengthen the working hours because of special circumstances.

"But it's common to see overtime work, especially in some internet companies," he said. "It's okay when the company asks the employee's permission to work overtime and pays the overtime wage.

"I've seen the sharp words of Chen and it's understandable as the company encroached on his right to rest."