Boris Johnson “peddled racial hatred” during the EU referendum campaign, peers were told as they discussed reports of racial attacks and abuse in the wake of the vote.

Labour’s Lord Dubs, who has campaigned on behalf of child refugees, said the immigration argument had won the referendum for the Leave camp, and this had resulted in hate crime.

In his criticism of the leading pro-Leave campaigner and Tory leadership favourite, Lord Dubs highlighted Mr Johnson’s warning that Turkey was about to join the EU.

The issue of the country’s likely accession to the bloc was deeply divisive during the referendum, with the Brexit camp accused of “scaremongering” after it claimed Turkish membership would lead to an influx of criminals to the UK, while also putting public services under pressure.

Lord Dubs, a former child refugee who escaped the Nazis by the Kindertransport, told peers that since the “wonderful days” of the London Olympics the UK had become “small, inward-looking and mean-minded”.

He said: “If ever the country needed leadership to tackle hate crime, leadership to condemn those awful people in our society who are taking advantage of minorities in this country, if ever there was time for leadership it is now.”

Lord Alf Dubs

Lord Alf Dubs

Lord Dubs added: “I am dismayed that someone who wants to be Prime Minister of this country peddled racial hatred, peddled opposition to migration by saying millions of Turks were going to come to this country.

“And after the referendum he then says it wasn’t about immigration at all.

“Anybody who knocked on doorsteps knows there was one issue that won the referendum for the Leave campaign and that was immigration.

“It was the immigration argument that did it and the hate crime is a result of that immigration argument.”

Opposition spokesman Lord Rosser pointed to reports of racial abuse and attacks following the EU vote.

He said: “All this was unleashed by the campaigning during, and outcome of, a referendum that was called not in the national interest but because of splits in the Conservative Party.

“The result of the referendum has emboldened those with feelings of such hatred, because in the light of the tenor of much of the campaign and its concentration on migration, such people now feel that the result has been an indication of support for their abhorrent views, and has given those abhorrent views a level of respectability that they did not have before.”

Former Metropolitan Police chief and independent crossbencher Lord Blair of Boughton argued hate crime should carry an automatic prison sentence.

He said: “There is no point in the police arresting people for these crimes and the Crown Prosecution Service then putting them in front of the courts unless the courts do something about it.

“I am not a natural hanger and flogger but a clause in the Policing and Crime Bill saying that the starting position for hate crime is a custodial sentence would send a message.

“We did exactly that regarding the possession of knives during the knife-crime epidemic.

“We said that the starting point was a custodial sentence, and I firmly suggest that the Government bring forward an amendment to that effect in committee.”

Communities minister Lord Ahmad of Wimbledon told peers: “I shall leave no stone unturned in ensuring that we eradicate all levels of hate crime.”