Lord Howard told Silver he should be “thoroughly ashamed of himself”, pointing out that former Labour leader Ed Miliband had proposed something similar, as had former prime minister Gordon Brown in more direct terms: “He wanted British jobs for British workers.”

Howard said of Silver’s complaint: “What he’s doing is taking what is a well intentioned piece of legislation into disrepute. The meaning behind the legislation is very important. It is meant to deal with hate crimes.”

He added that Howard had been “totally unable to justify himself in the face of your (Neil’s) questions”.

The interview ended with Silver revealing that he was not a “normal complainer”, but was working on one about Prime Minister Theresa May and her comments about “expelling all foreign doctors”

Following news of the police intervention, the Liberal Democrats issued a statement condemning Rudd, saying her speech was the “kind of incident that would once have been associated with a UKIP councillor, now it is happening to a Conservative Home Secretary”.

Liberal Democrat Alistair Carmichael said: “That (Rudd’s speech) is a sign of how much this Conservative Brexit government has abandoned the centre-ground and embraced the politics of Nigel Farage.

“I do have concerns over whether the police should be investigating a politician’s speech, but Amber Rudd should certainly investigate her own conscience over these grubby and divisive remarks.”

The policy of blanket recording of all hate incidents was set out in 2014 by the College of Policing and was backed by Rudd last year.

In the government’s action plan on hate crime, published last July, Rudd said that increased reporting of incidents would help police to deal with hate crime more effectively. 

In a statement at the time she said: “Those who practise hatred send out a message that it’s okay to abuse and attack others because of their nationality, ethnicity or religious background. That it’s okay to disregard our shared values and promote the intolerance that causes enormous harm to communities and individuals.

“Well, I have a very clear message for them. We will not stand for it. Hatred has no place whatsoever in a 21st century Great Britain that works for everyone.”

A Home Office spokesman told the Times that Rudd’s speech “was not a hate crime”.