Christianity is in danger of becoming extinct in its ancient homelands because of a rising tide of sectarian attacks, a senior minister will warn on Friday. 

Violence against Christian worshippers and other religious minorities by fanatics has become a "global crisis" and is the gravest challenge facing the world this century, Baroness Warsi will say. 

"A mass exodus is taking place, on a Biblical scale. In some places, there is a real danger that Christianity will become extinct," she will say at a speech at Georgetown University in Washington.