TAIPEI - Taiwan's Health Minister Chen Shih-chung resigned on Thursday (July 14), with immediate effect, to run for Taipei mayor.

The face of the island's Covid-19 fight, Mr Chen went from a relatively anonymous administrator to become possibly the most popular health minister in Taiwan's history for his success at keeping Covid-19 case numbers low in the first year of the pandemic.

Leading the Central Epidemic Command Centre, he implemented strict quarantine and border control rules, and made headlines in Japanese newspapers when reporters found out that he had not taken a day off in months.

"The virus isn't taking a day off, is it?" he famously replied when journalists asked about his hectic work schedule.

Cartoonists released free sketches of him that people printed out and propped up at work desks, while office buildings and restaurants had his photo at their main entrances - a droll reminder for Covid-19 vigilance as "Chen is watching".

Premier Su Tseng-chang on Thursday lauded Mr Chen for his hard work and ability to "keep the people united, handle difficulties as they come, and keep the impact of the pandemic to a minimum".

"We are very grateful to the minister... He has been in the position for five years and five months, and is currently Taiwan's longest-serving health minister in 25 years," he said.

A new health minister has not been named.

Calls for the ruling Democratic Progressive Party (DPP) to nominate Mr Chen to run for Taipei mayor - and even for president - began spreading on social media in 2021.

Mr Chen has now answered that call, following confirmation on Wednesday by the DPP that he would be running in the mayoral race in November.

This, however, comes at a time when his popularity has taken a hit, following Taiwan's worst Covid-19 outbreak. Cases have shot up from below 1,000 cases in the first week of April to around 50,000 new local cases daily for most of May and June.

"I think the government is doing badly at controlling Covid-19, there's no way I'm going to vote for Mr Chen when he runs," said Ms Wu Chen-lan, 48, who runs a bed and breakfast in Taipei's Zhongshan District with her husband.

Others have been quick to harp on Mr Chen's claim last October that while he was open to running for office, he would consider the possibility "only when the light at the end of the tunnel is visible", with regard to Taiwan's Covid-19 situation.

Mr Chen was also accused of "running off when things got rough" by some from the main opposition party, the Kuomintang (KMT).

His main mayoral rival Chiang Wan-an, a KMT lawmaker, blasted him for abandoning his post before the pandemic ended.

"I'd like to remind the minister that recently, there are still over 20,000 cases and nearly 100 deaths daily. Vacating your post now is not honourable, it's called running away... The people of Taiwan will forever remember this," said Mr Chiang.

In response, Mr Chen said on Thursday: "I was an administrative officer and I did my job conscientiously every day I was in office. Now that I'm leaving, it's not running away - I come and go when the orders tell me to."

Mr Chiang is currently leading opinion polls with an approval rating of 35.2 per cent.

Mr Chen's 29.9 per cent approval is a slight jump from 25.3 per cent in June, but a far cry from his 35.1 per cent score in online news site  ETtoday's survey in September 2020, at the height of his popularity.

In third place with an approval rating of 25.9 per cent is Taipei Deputy Mayor Huang Shan-shan, the right-hand woman of current Mayor Ko Wen-je during his two terms in office.