A teacher told a class that included Jewish children that they had "better finish off your work quick, or I’ll ship you all off to the gas chambers".

The supply teacher, who was teaching French, made the comment during a class on Thursday at Newberries Primary School in Radlett, Hertfordshire. 

The school said the teacher would not be returning.

In messages sent by parents to each other on WhatsApp after the incident, seen by the JC, one said there was a "high Jewish concentration of kids in the class".

Almost a third of the Radlett population identifies as Jewish — more than 2,200 in total.

The parents' messages claimed one child in the Year 6 class - of 10 and 11-year-olds - challenged her and she tried to apologise.

Some parents are understood to have threatened to withdraw their children unless action was taken.

In a statement, the school said: "We can confirm that last week we were made aware that an alleged racist comment had been made by an agency teacher working within the school.

"We acted on this immediately and our governors and leadership team are undertaking a full investigation.

"The agency teacher will not be returning."

In a message to parents, the school's joint headteachers said: "As a result of recent events, we would like to reassure you we are doing everything we can to embrace and celebrate diversity.

"As in previous years, the school is arranging visits from local religious leaders from differing faith groups. This year we are particularly asking for the focus to be on strengthening the important messages of religious tolerance and respect."