David Cameron has been criticised for referring to the people living at the camp in Calais "bunch of migrants".
The prime minister deployed the phrase while going after Jeremy Corbyn and Labour during PMQs on Wednesday. "Look at their record over the last week. They met with the unions and gave them flying pickets," he said.
"They met with the Argentinians, they gave them the Falkland Islands. They met with a bunch of migrants in Calais they said they could all come to Britain. The only people they never stand up for are the British people and hardworking taxpayers."
Corbyn has proposed Britain allow in refugees who have a family link to Britain. However Cameron has dismissed the idea, claiming it would make the French border a magnet for more migrants."
Former Labour leadership candidate Yvette Cooper demanded the prime minister withdraw his remark given today was Holocaust Memorial Day.
She asked Commons speaker John Bercow immediately after prime minister's questions: "Doesn't he think it was inappropriate of the prime minister to use language referring to the refugee crisis in Europe and talk about a 'bunch of migrants'?"
Cooper said Cameron should use "much more statesman-like language" about the need to "build a cross-party consensus on such a complex and sensitive issue".
Cameron was also criticised by shadow home secretary Andy Burnham and former shadow cabinet minister Chuka Umunna.
Liberal Democrat leader Tim Farron said Cameron "diminishes his office and our country" with his comment. "Whether Mr Cameron planned to use this phrase in advance or whether it was an off the cuff throw away remark it shows his true attitude towards those most in need," he said.
On his LBC phone-in, Alex Salmond was asked if felt Cameron's comments painted migrants as "sub-human and was effectively "hate-speech". He replied: "I agree with you".
Salmond also claimed Cameron used the term to deflect attention away from the Google tax deal. He said: "I think David Cameron learnt a bit from the Australian maestro of spin, and disgusting spin at that".
Several political commentators also speculated as to whether the phrase had been deliberately used to distract from the ongoing row over whether the government had allowed Google to get away with not paying enough tax.
The term "dead cat" strategy, made famous by Cameron's Australian general election guru Lynton Crosby, refers to a politician making a deliberately provocative statement to change the terms of debate.
Conservative Anna Soubry told BBC Radio 4 she may "not necessarily" have used the same langauge as the prime minister, but dismissed the suggestion Cameron's line had been scripted as "silly".
"What everybody forgets is, in the heat of thing, one says things that you might say in a conversation which you might not necessary say when it's analyses and picked apart," she said. "We all use slang."
"I will not criticize the prime minister on this. I know when you are standing at the Despatch Box .. you've for all the row and noise 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'."
"I would be amazed if that was a scripted line," she added. "I don’t believe that for one moment. If anyone says that they are being silly."
The row echoes one from last July, when Cameron was criticised for branding the migrants and refugees gathered at the Calais camp as "a swarm".
Labour's the deputy leader, Harriet Harman, said at the time the prime minister "should remember he is talking about people and not insects".