CAIRO: The split between Islamists and secularists that has tainted some of last year’s Arab uprisings is souring relations within Syria’s opposition, threatening European and American hopes of a united political front against the regime of President Bashar Assad.

Activists say that the Muslim Brotherhood – the Middle East’s most popular Islamist organization which has emerged as the strongest political force in post-revolution Egypt – has developed increasing control within Syria’s leading opposition movement, the Syrian National Council.