That's four times greater than the Muslim population of the EU now.
At the moment, only around 5 per cent of people in the EU's 27 Member States are Muslim.
The investigation also predicts that Britain will overtake Germany to beome the EU's most populous nation by 2060, with 77 million people. Germany's population is shrinking.
A fifth of European Union will be Muslim by 2050
Britain, Spain and Holland will have an even higher proportion of Muslims in a shorter amount of time, an investigation by The Telegraph shows.
By Adrian Michaels
08 Aug 2009
On a hope and a prayer: lack of debate over influx of Muslims, some experts claim Photo: REUTERS
Last year, five per cent of the total population of the 27 EU countries was Muslim.
But rising levels of immigration from Muslim countries and low birth rates among Europe's indigenous population mean that, by 2050, the figure will be 20 per cent, according to forecasts.
Data gathered from various sources indicate that Britain, Spain and Holland will have an even higher proportion of Muslims in a shorter amount of time.
The UK, which currently has 20 million fewer people than Germany, is also projected to be the EU's most populous country by 2060, with 77 million people.
The findings have led to allegations that policy-makers are failing to confront the widespread challenges of the "demographic time bomb".
Experts say that there has been a lack of debate on how the population changes will affect areas of life from education and housing to foreign policy and pensions.
Although some polls have pointed to a lack of radicalisation in the Muslim community, little attention is being given to the integration of migrants, it is claimed, with fears of social unrest in years to come.