A government-sponsored report into persecution against Christians around the world has warned that they risk being "wiped out" in some areas, particularly the Middle East.
That is one of the preliminary findings of a review into the Foreign and Commonwealth Office's support for persecuted Christians that was launched earlier this year by Foreign Secretary Jeremy Hunt.
The report, overseen by the Bishop of Truro, said the level of persecution being experienced by Christians worldwide was approaching the UN definition of genocide.
"Evidence shows not only the geographic spread of anti-Christian persecution, but also its increasing severity. In some regions, the level and nature of persecution is arguably coming close to meeting the international definition of genocide, according to that adopted by the UN," the report said.
It warned that extremist groups in places like Syria, Iraq, Egypt, north-east Nigeria and the Philippines were working with the goal of the total "eradication" of Christians.
It said the "intent to erase all evidence of the Christian presence" in these countries had been "made plain" by violent actions such as the removal of crosses and the destruction of church buildings and other Christian symbols, while the abduction of Christian clergy, it said, represented a "direct attack" on the church's structure and leadership.
"Where these and other incidents meet the tests of genocide, governments will be required to bring perpetrators to justice, aid victims and take preventative measures for the future," the report said.
"The main impact of such genocidal acts against Christians is exodus. Christianity now faces the possibility of being wiped-out in parts of the Middle East where its roots go back furthest. In Palestine, Christian numbers are below 1.5 per cent."
A report of the bishop's full findings is to be released in the summer.
Foreign Secretary Jeremy Hunt said: "I asked the Bishop of Truro to deliver an independent, honest, unflinching and hard-hitting report. What he has delivered to me today makes for a truly sobering read. I thank him and his team for their hard work.
"The interim report comes just after the appalling attacks at Easter on churches across Sri Lanka, the devastating attack on two mosques in Christchurch, and most recently the San Diego synagogue shooting.
"There is nothing more medieval than to hate someone on the basis of their faith. That it is on the rise should shock us all.
"I look forward to seeing the Bishop's final report in the summer, and identifying further specific steps the FCO can take to do more to address the fate of persecuted Christians around the world."
Open Doors, a ministry that supports persecuted Christians worldwide, said the report made for "grim reading".
"The recent attacks on churches in Sri Lanka show that change is needed urgently," said Henrietta Blyth, CEO of Open Doors UK and Ireland.
"The UK government needs to work with religious leaders who stay serving in the most dangerous places. It needs to recognise, as the report shows, that vulnerabilities around faith and religion are as important as vulnerabilities around gender, ethnicity, disability or age."