SP, I've seen your link. Shame the estimate stops at 2050, but nevertheless the findings appear to agree with me.
//Most of the “native” populations of Europe are failing to have enough children, while birth rates are higher among Muslim immigrant populations, so it seems inevitable that the British Muslim population will rise in the coming decades.
But it’s equally clear that the gap in fertility between Muslim and non-Muslim will continue to lessen over time, as it has in recent decades.//
Bearing in mind that the Muslim population consistently breeds at a higher rate than the rest of the population, it has to lessen very significantly indeed before it will make a difference to future demographics. To put it simply, more kids inevitably leads to more kids.