As foreign-born workers and their allies prepare to denounce the immigration policies of President Trump in a national "Day Without Immigrants" protest Thursday, their plans pose a particular challenge for America's $550-billion-a-year restaurant trade, in which immigrants — some here legally, some not — play essential roles as chefs, line cooks, servers, and dishwashers.

Organizers of the one-day strike are urging all businesses owned or staffed by immigrants — not just restaurants — to close. They want employees to stay home from any establishment that remains open, and customers to stay away, to illustrate what would happen if the United States were to be purged of undocumented workers.

>> Follow along here for updates on the protest throughout the day

Immigrants' contributions to local economies will be highlighted at a rally from noon to 3 p.m. at Thomas Paine Plaza at the Municipal Services Building, said Carmen Guerrero, a cofounder of the advocacy group Coalición Fortaleza Latina.

In Philadelphia, with its vibrant restaurant scene, workers in several establishments say they plan to take part in the boycott, giving up wages in exchange for raising awareness.

Greg Dodge, whose company owns Tredici Enoteca and Zavino, at 13th and Sansom Streets, and Zavino University City, 3200 Chestnut St., said management decided to close for the day, idling 125 employees. He estimated that 90 percent of his kitchen workers are Latino and said three of his company's four executive chefs are Latino.

"I've been in the business since I was 14," said Dodge, "and in 30 years I have never seen such an outpouring of support for a cause. We want to support our employees. There's no political agenda here. If an employee wants to make a point, the least I can do is support him. … To not listen to them would be a mistake."

Sam Mink, owner of Mission Taqueria and the Oyster House in Center City, said he would pay staff whether they worked or joined the protest. Immigrants are "our backbone," said chef Brett Naylor. "And I consider them part of my community and friends. It's inspiring [what] they are doing.  Takes conviction, guts."

The chef Jose Garces, a son of Ecuadoran immigrants who owns more than a dozen restaurants in and around Philadelphia, said his enterprises would be open, but he would not penalize any employee who chose to participate in the protest.

"We recognize the immigrant community is an essential part of the hospitality industry.  Since 2012, the Garces Foundation has provided health, nutrition, and education resources for immigrant families in need," he said through a spokeswoman. "We support the right for hospitality-industry employees to have their voices heard."

In Washington, celebrity chef Jose Andres decided to close five of his restaurants.  Andres is battling Trump in court because the Spanish-born chef pulled out of his planned restaurant at Trump's Washington hotel after candidate Trump repeatedly disparaged Mexican immigrants.

Beefsteak, the vegetable-focused restaurant in University City that Andres conceived, will be open Thursday. The location is owned by the University of Pennsylvania, which had no plans to close it, a restaurant manager said.

Standard Tap, a popular bar in Northern Liberties, is supporting the protest by not operating its kitchen, said co-owner Paul Kimport. The bar will be open, serving fresh baked pretzels. Kimport said 20 percent of all drink and pretzel sales will be donated to the ACLU of Pennsylvania, which has defended immigrants and refugees in court.

Tria and Tria Taproom "are proud to be owned and staffed by immigrants and descendants of immigrants," owners Jon Myerow and Michael McCaulley said in a statement. "We would not be able to open our doors without them, and ... we stand in solidarity with them. We will serve only wine, cheese and beer... as our kitchens cannot open without the hard work and dedication of our entire team."

The owners said they would donate $1 from every wine, cheese, and beer sale to the Pennsylvania Immigration and Citizenship Coalition, an advocacy group.