Watch the moment David Cameron silences his own MPs with 'bunch of migrants' comment

The Conservative backbenches, normally right behind the PM both figuratively and literally, seemed as shocked as everyone else

David Cameron has been attacked on all sides after he dismissed refugees in Calais as “a bunch of migrants”, with Labour and the Lib Dems in particular quick to seize on the comment.

The use of the phrase in Prime Minister’s Questions has been deemed all the more insensitive as it came on Holocaust Memorial Day, as Europe remembers another time when millions were forced to flee persecution and war.

But what was perhaps most telling about the Prime Minister’s poor choice of words was the reaction from his own MPs in the Commons, who generally cheer his every word.

In what appears to be something of a pre-prepared jibe, Mr Cameron denounced Jeremy Corbyn and shadow Chancellor John McDonnell by saying “the idea that those two right honourable gentlemen would stand up to anyone in this regard is laughable”.

He said the pair “met with the unions and gave them flying pickets” and “met with the Argentinians and gave them the Falklands Islands”, each time receiving a laugh and a cheers from the benches behind him.

When the Prime Minister then finished the trio of apparent criticisms by saying they “met with a bunch of migrants in Calais and said they could all come to Britain”, he was met with stony silence.

As he moves swiftly on, the Foreign Secretary Hilary Benn can be seen mouthing the phrase repeatedly in disbelief, while other MPs can be heard repeating “bunch of migrants” in shock.

Mr Cameron’s own spokesman has tried to deflect attention from the wording he used, insisting that the public would be “more concerned about Labour’s immigration policy”.

Asked if the phrase “bunch of migrants” should be seen as pejorative, the spokesman avoided the question, saying “the Prime Minister thinks that the key thing here is to get the policies right”.

Seeming to confirm the view among his own Conservatives that Mr Cameron had misspoken, business minister Anna Soubry told the BBC’s World At One programme she was “sure” the Prime Minister meant to say something else.

She said she “wouldn’t necessarily” have used the phrase herself, saying: “I will not criticise the PM on this one because I know that when you're standing at the despatch box ... and you have all the noise and the row around you it is very easy to use a word which on reflection may not be the best way.

“I am sure he meant to say a group, but we all use slang.”

Ms Soubry said she would be “amazed” if that part of Mr Cameron’s answer had been a scripted line, however.

Away from the political reactions, the Refugee Council said it was “disappointing” to hear the Prime Minister use such language and called on him to show leadership in the “desperate” situation.

Lisa Doyle, the Refugee Council's head of advocacy said: “When we are facing the greatest refugee crisis of our time, it is disappointing the Prime Minister is using flippant remarks to score political points.

“We have all seen the pictures of the desperate conditions people are living in across Europe, including just miles from the UK's border. The Prime Minister should be showing political leadership and work with other European countries to ensure that people can live in safety and dignity.”