San Francisco Mayor London Breed plans to ban commercial evictions for small- and medium-sized businesses impacted by the new coronavirus. The move, announced Tuesday, comes as businesses and workers across the Bay Area stare down the existential economic threat posed by the pandemic and the shelter-in-place order it’s prompted.

Under Breed’s directive, businesses that can’t afford to pay rent because of lost revenue or other economic impacts tied to the coronavirus will not be evicted. The directive is expected to take effect Wednesday and will last for at least 30 days.

The directive follows an executive order Gov. Gavin Newsom signed Monday that allows cities to ban local evictions for residential and commercial tenants.

In San Francisco, businesses with gross receipts of less than $25 million would be eligible for the extra eviction protections.

“The steps we have taken to protect public health are absolutely necessary, but we know that they are having a huge impact on our workers and our businesses,” Breed said in a statement. “Now that the Governor has waived laws allowing us to prevent commercial evictions, we are taking action to make sure that our small businesses are not displaced as a result of the economic impact caused by coronavirus.”

Supervisor Dean Preston also plans to introduce legislation Tuesday that would ban commercial evictions for non-payment of rent. Breed and Preston’s offices did not collaborate on their respective measures, which are nearly identical in their intent.

“I’m glad to be stepping up to prevent businesses from being displaced during this state of emergency,” Preston said in a statement. “We must preserve our small businesses and make sure they are in a position to weather this storm.”

San Francisco has previously made $10 million available to support over 16,000 additional weeks of sick leave pay, providing coverage for up to 25,000 private-sector employees in the city.

With residents ordered to shelter in place and businesses in all but a handful of sectors ordered to shutter, San Francisco, along with the rest of the region, is bracing for a major economic impact as a result of the coronavirus. San Francisco Controller Ben Rosenfield said the city alone could see tens of millions of dollars in lost revenue for the first quarter of the year alone.

Business owners and employees were pitched headlong into a fog of uncertainty following Monday’s shelter-in-place order. For many, relief will not come soon enough.

“As a result of the public health order I had to close my salon immediately and have no other source of income. I depend on my daily bookings to make the rent every month and at this point I would not be able to pay April’s rent,” said Dimitri Cornet, owner of Werk Salon in the Mission District, in a statement.

“A moratorium on evictions would allow me the time to recover bounce back and keep my business open.”

Foot traffic has evaporated in front of Danel de Betelu’s French bakery and tea salon, Maison Danel, at 1030 Polk St. He opened it just weeks ago. Amid the citywide lockdown, he’s had to cancel hundreds of reservations and has told his 12-person staff to stay home.

“It’s nobody’s fault, I understand the circumstances, obviously. But it’s a nightmare,” de Betelu said. “I want to be safe, but the city is shutting down and we just have no clue about what’s going on. We know we have to shut down and not make money. That’s all we know.”

Dominic Fracassa is a San Francisco Chronicle staff writer. Email: dfracassa@sfchronicle.com Twitter: @DominicFracassa