Nigel Farage has been accused by Nick Clegg of exploiting Wednesday's terrorist attack in Paris for his own political gain, after he suggested multiculturalism was to blame.
The deputy prime minister told LBC radio this morning he was "dismayed" at the Ukip leader's response to the "horrific, cold hearted, cowardly attack" on the offices of French satirical magazine Charlie Hebdo in which 12 people were killed.
"Let's remember if this does come down, as it appears to be the case, to two individuals who have perverted the cause of Islam to their own bloody ends, the greatest antidote to the perversion of that great world religion of Islam are law abiding British muslims themselves.
"To immediately somehow suggest that somehow or to imply that many, many, British muslims who feel fervently British but are also proud of their muslim faith are somehow part of the problem is firmly grabbing the wrong end of the stick."
Clegg added: "I am dismayed that Nigel Farage immediately thinks, on the back of the bloody murders we saw on the streets of Paris yesterday, his first reflex is to make political points."
- Live Updates: the latest from Paris
Farage said the attack was the result of "having a fifth column" living in Western countries opposed to their ideals. He said the the attack was "truly horrific" and had "some very worrying implications for our civilisation - free speech, satire, all things that Western countries believe in and love and have enjoyed for centuries".
He told Channel 4 News: "There is a very strong argument that says that what happened in Paris today is a result - and we've seen it in London too - is a result I'm afraid of now having a fifth column living within these countries.
"We've got people living in these countries, holding our passports, who hate us. Luckily their numbers are very, very small but it does make one question the whole really gross attempt at encouraged division within society that we have had in the past few decades in the name of multiculturalism."
French police say they have identified three men as suspects in the deadly attack. The suspects were named as brothers Said Kouachi and Cherif Kouachi, French nationals in their early 30s, and 18-year-old Hamyd Mourad, whose nationality is unclear.
One official said the men were linked to a Yemeni terrorist network.
France's president Francois Hollande has declared a national day of mourning today following the bloody raid on the Paris headquarters of the magazine Charlie Hebdo, which angered some Muslims after publishing cartoons of the Prophet Mohammed.
In the UK, Home Secretary Theresa May will chair a meeting of the government's emergency committee Cobra today, while Prime Minister David Cameron has offered the assistance of British spies to help French agencies investigate the atrocity.