The Ukip leader has been accused of a racial slur after commenting that people should be concerned if a group of Romanians moved in next door to them. Asked by LBC Radio why it would be ok for Germans to move in and not Romanians was, he replied: "You know what the difference is."
Lammy, the MP for Tottenham said on Monday: "What Nigel Farage said over the weekend was racist. So I'm clear, he's a racist."
The Tottenham MP, whose parents moved to Britain from Guyana before he was born, told the BBC's Daily Politics programme that the Ukip leader's words reminded him of the racism experienced by his mother and father.
"Let's be clear I am from a background where my parents arrived here as immigrants. I remember a context in which some people said, 'you don't want these people living next door to you', that was racist," he said.
The Labour MP said Farage's comment was "deeply nasty". He added: "We have seen this before in Europe, in times of recession and depression, and we must take that kind of slur extremely seriously."
Lammy's direct branding of Farage as "racist" is at odds with Ed Miliband's decision to shy away from a similar criticism. He told BBC Radio 4's Today programme this morning: "I think, though, our politics is sort of disagreeable enough without political leaders saying about other political leaders 'they are a racist'.
The Labour leader added: "I think it was deeply offensive, I think it was wrong what he said. I don't know Nigel Farage very well, I think he made one remark which was completely wrong, completely out of order, and was a slur. Apparently he's said he got it wrong, he should certainly say he's got it wrong."
But Lammy said it was not helpful "to get in a pedantic discussion" about he difference between a racist slur and being a racist. "He [Farage] is the leader of a national party she should not be slurring whole communities of Romanians," he said.
And shadow home secretary Yvette Cooper said of Farage's comment: "It is racist to some how stir up fears about Romanians living next door."
The difference of approach reflects a tension within Labour about how to take on Ukip. Southampton MP John Denham recently warned the party had made a "complete hash" of dealing with the anti-immigrant party.
David Cameron said today that Farage had said some "really pretty unpleasant things" but stopped short of calling the Ukip leader racist. "I will leave others to judge but what I have heard from some of the candidates, some of the donors to the party is a succession of pretty appalling things," he said.
On Monday Ukip took out a full-page advertisement in a national newspaper to insist the party was not racist but repeated its warning about the risk posed by organised criminal gangs from Romania. Farage said his comments about people being right to be concerned if a group of Romanian men moved in next door had caused a "predictable storm of protest and accusations of racism".
The Ukip leader initially stood by his remarks, which came during a bruising interview with LBC, but last night he said: "Do you know what, in life sometimes people get things wrong." He told BBC News: "I regret the fact that I was completely tired out and I didn't use the form of words in response that I would have liked to have used.