Sadiq Khan has claimed David Cameron was "writing propaganda for the English Defence League" when he made comments about multi-culturism.
Tooting MP Sadiq Khan believes Conservatives have been embarassed by Mr Cameron's speech Mr Cameron told an audience in Germany the Government should no longer tolerate and engage with extremist groups whose members did not believe in crucial western and British values.
Speaking at the Munich Security Conference, he said: “Let's properly judge these organisations... do they believe in universal human rights - including for women and people of other faiths?
“Do they believe in equality of all before the law?”
His remarks, which came on the same day the EDL - an anti-Islamist street protest movement - had arranged a march in Luton, prompted a fierce reaction from Mr Khan, who branded the Prime Minister a far-Right “propagandist”.
In response to Mr Khan's comments, Tory co-chairman Baroness Warsi called for an immediate apology.
She said: “For Sadiq Khan to smear the Prime Minister as a right-wing extremist is outrageous and irresponsible.
“David Cameron has made it clear that he wants to unite Britain around our common values and he has done so in measured language.
“Extremism and Islam are not the same thing.”
But this week, a seemingly unrepentant Mr Khan said: “The Conservatives are trying to create an artificial row with me because they realise now that they have been embarrassed by the timing of Cameron's speech.
“On the day that the EDL are marching through Luton and making British Muslims fear to step outside their own homes, it was highly unwise for the PM to make a speech like this spun the way it was.
“Clearly his speech contradicts what Baroness Warsi said two weeks ago and the fact that it has been welcomed by Nick Griffin and members of the EDL tells its own story.”