Restaurateur Richard Caring is reported to have emailed his staff members in an attempt to allay the fears of international workers following the "absurd" Brexit vote.
The owner of Caprice Holdings, which operates restaurants including Le Caprice, The Ivy, Sexy Fish and Scott's, is thought to have said he will fight "tooth and nail" to protect the rights of workers from other countries.
According to the Evening Standard, the restaurant tycoon told staff they should have "no concerns" about being able to stay in the country after the UK voted to leave the European Union last month.
Caring is believed to have contacted staff after a number of workers told management they were worried about their status following the referendum result on 23 June.
In the email, he said: "I would like to say that as a company we are proud to have you working with us and would also like to assure all of our immigrant partners that they should have no concern regarding their status in the UK on a long-term basis if that is what they so choose.
"I cannot believe that at any time anyone who has been working in this country for a period of time will be asked to leave because they are classified as an immigrant."
He added: "I would assure you that this will not happen, will not be allowed to happen and that I, along with the vast majority of employers in this country, would fight tooth and nail to ensure your stability and tenure so that you might carry on and be welcome as a solid and respected part of UK industry."
Caring went on to say the UK is not racist despite comments from "the tiniest minority of the population which every country has to some degree".
He said: "There has been talk of foreigners not working or being welcome in this country… these people are ignorant and their voice will not be heard."
A spokesperson for Caprice Holdings could not be reached by The Caterer.