The Tory idea to make firms list their foreign workers is worse than Donald Trump's plan to ban Muslims from entering the US, David Cameron's former policy guru has warned.
Steve Hilton, who broke with the ex-PM to back Brexit, was scathing about Home Secretary Amber Rudd's suggestion, which provoked uproar after being trailed at the Conservative conference this week.
Ministers might as well announce that "foreign workers will be tattooed with numbers on their forearms," Mr Hilton wrote in the Sunday Times.
The former head of policy at No 10 warned that forcing companies to reveal all their foreign workers would be " divisive, repugnant, and insanely bureaucratic".
Ms Rudd told people not to brand her a "racist" after the idea was widely condemned, with Labour calling it xenophobic.
The initiative was also attacked by Ukip MEP Roger Helmer, who said: " This idea that companies should provide lists of foreigners - if we had suggested that, if Ukip had suggested that, they would have been shouting 'Fascist' up and down the street. I personally think that is a step too far."
Mr Hilton also accused Prime Minister Theresa May of being " incompetent and irresponsible" for allowing the international community to think Brexit would cut UK off from rest of the world.
A Home Office spokesman said: " This is not about listing foreign workers or so-called 'naming and shaming' of companies. The proportion of international workers in a company is one of the pieces of information that companies may be asked to provide to the Government.
"This information will not be published. This already happens in the US and is one of several proposals we will be consulting on as part of our work to ensure that companies take reasonable steps to recruit at home before looking to bring in workers from abroad.
"The purpose of having a consultation is so that we can listen to business and use that feedback to inform our decisions".
This is one of the proposals the Home Office will consult on to tighten the Resident Labour Market Test, which businesses have to undertake when they want to recruit non-EU workers, to demonstrate they are filling genuine gaps in the labour market.
At the moment that requires a company to advertise the role for 28 days and demonstrate that no qualified resident worker could fill it.
A Home Office source said: "This is a wilful misinterpretation of one question in a consultation document - the whole point of which is to seek views on the best approach."