Rudd's speech at the Conservative Party conference caused controversy with the claim that foreign workers should not be able to "take the jobs that British people should do."
It was billed as naming and shaming firms who do not employ enough British workers.
Now the Home Secretary's brother, Roland Rudd, has hit back, criticizing his sibling.
"In a democracy there is always a spectrum of views," he wrote in an Evening Standard article.
I find nothing to disagree with @RolandRudd here — Labour must fight for single market access and give not 1 inch to anti-migrant prejudice https://t.co/SuKgn3UfX3
— Paul Mason (@paulmasonnews) October 6, 2016
"Those of us who want a sensible Brexit, who want Britain to remain a beacon of tolerance and who find the denigration of non-British workers appalling have a duty to speak out," he added.
The Home Secretary's brother was a prominent campaigner for a Remain vote in the EU referendum and has since founded the Open Britain campaign.
.@RolandRudd Businesses want a sensible #Brexit, staying in the Single Market to protect jobs, investment & trade #peston
— Open Britain Press (@open_britpress) October 2, 2016
The family feud illustrates the growing dividing lines in Britain on the issue of immigration following the Brexit vote in June.
In the article, Mr. Rudd says that the government is being more divisive than healing.
"Try and point out this U-turn and you are dismissed as a bad loser; try and stand up for a multiracial Britain and you are labeled part of the liberal elite; point out the £20 billion [US$24,68 billion] net contribution from immigrants over a decade and you are told you are not listening to the people; oppose hate crime and you are mocked for political correctness.
"It is easier to vilify foreigners in the new Britain than it is to espouse European values. No wonder most of the Remainers have headed for the hills," Mr. Rudd wrote.
Meanwhile, a search for Amber Rudd on Google also shows up some unfortunate results.
The top suggested search is Mein Kampf, the autobiography of Nazi leader Adolf Hitler. This follows a viral tirade by LBC Presenter James O'Brien, who compared sections of Amber Rudd's speech to the second chapter of the dictator's book.
But the Home Secretary has since hit back at critics, saying, "dont call me a racist" for talking about immigration.
