Fear that Western countries are undergoing a process of 'Islamisation' was the main motivation of Norwegian terrorist and mass murderer Anders Behring Breivik. But it can also be seen in Melanie Phillips' columns in the Daily Mail, in bestselling books, and on the placards of the EDL. It also happens to be nonsensical.
It really shouldn't be necessary to make the argument that Britain is not in the process of Islamic takeover, but sadly, it is. Seeing diminutive football hooligan (Luton Town, tragic) and self-appointed leader of the EDL "Tommy Robinson" spreading his poison on Newsnight without challenge led me to have a quick look for writing on the subject backed up by evidence, rather than the prejudices of a former BNP candidate .
I didn't have to look long. I've attached the pdf of Debunking the Islamisation Myth by Edmund Standing. There are things to disagree with in his political perspective, but that's by the by, as the essay is a very clear demolition of the Islamisation argument.