The Archbishop of Canterbury and the head of the Catholic Church in England and Wales have called on the Government "to take meaningful action" to promote religious freedom and protect Christians being persecuted for their faith.
The call came in a joint submission to an independent review commissioned by Foreign Secretary Jeremy Hunt earlier this year to assess the support being provided by the Foreign and Commonwealth Office for persecuted Christians worldwide.
Archbishop Justin Welby and Cardinal Vincent Nichols said they wanted to see the Government promote religious freedom as a "fundamental human right" and build advocacy on this issue into its work across a range of policy areas, from foreign relations to aid, security, trade and asylum.
In addition to Christians, the Church leaders said the Government should also work to protect freedom of religion and belief for people belonging to different faiths as well as non-believers.
"Christians form an important part of the social fabric in almost every country of the world. Yet in many places, our Christian sisters and brothers face persecution of an intensity and extent unprecedented in many centuries," their submission reads.
It continues: "We must remember, too, that these threats to freedom of religion or belief are not restricted to Christians alone. Rather, it is a widespread experience of the followers of other faiths.
"Many are deprived of this basic expression of their human dignity. Similar threats are also faced by atheists and agnostics who seek to uphold crucial decisions of conscience.
"We ask Her Majesty's Government to take note of the practical recommendations offered by our Churches in this Submission and to take meaningful action not only in protecting Christians facing persecution but also in promoting freedom of religion and belief more widely."
Their call has the support of Archbishop Bashar Warda, the Chaldean Catholic Archbishop of Erbil in Kurdistan Iraq, where Christians were forced to flee in 2014 because of the onslaught of ISIS across northern Iraq.
Archbishop Warda said the UK Government's review into Christian persecution was a "courageous first step" in helping communities suffering for their faith.
"The next courageous step is to come and listen to those who suffer and witness the persecution, the destruction, the displacement and the frightening figures of persecuted flight," he said.
"The Church in England and Wales is a great support to us here in Iraq since the coming of ISIS in 2014. Cardinal Nichols made a great impact when he came here in 2015 to see and experience our situation at first hand."
The independent review was launched by Mr Hunt in January and is being led by the Bishop of Truro, Philip Mountstephen.
It aims to map levels of persecution and other discrimination against Christians around the world and make recommendations to the Foreign Secretary about whether changes need to be made to the UK's support for persecuted communities.
The review was launched days after a Catholic cathedral in the Philippines was bombed, killing 20 people and injuring over 100 others.
Launching the review, Mr Hunt voiced concern about the state of religious freedom in other countries too, including Egypt, Afghanistan, Somalia, Sudan, Libya, North Korea, and China.
He said he was launching the review "not just because freedom of worship is a fundamental human right, but because also freedom of worship is the invisible line between open societies and closed societies".
"Where freedom of worship is hampered or prevented, then usually that's a sign of lots of other things going wrong, and we wanted to make sure that the UK is doing everything to champion the values that we all believe in," he said.