King Charles remembered the plight of Christians facing persecution around the world, as he attended an atmospheric, candle-lit Advent service at Westminster Abbey.

The service, with a strong Orthodox Christian influence, along with Anglican and Catholic prayers, warned against religious discrimination, with a message from the King supporting those "in areas where it is not easy to live out one's faith".

There was also a seasonal message of hope in the winter gloom, with the King hailing "the light, hope and, above all, the peace of this season".

The King particularly seemed to enjoy the Advent hymn, O Come, O Come, Emmanuel, which he described in the Order of Service as "magnificent".

The service, conducted by the Dean of Westminster, the Very Reverend Dr David Hoyle, brought together a range of representatives of Christian denominations, including the Most Reverend Hosam Naoum, the Anglican Archbishop of Jerusalem and the Middle East.

It was a meditative service marking the approach of Christmas, and in many ways it was unorthodox, as well as Orthodox, with a colourful range of religious robes and a rich mix of different languages and musical styles.

The sermon was given by Cardinal Timothy Radcliffe, a senior Catholic clergyman, who spoke of the importance of rejecting intolerance and the "massive persecution of Christians in so many places".

He remembered the death of a bishop in Algeria, Pierre Claverie, who had been killed by Islamist extremists in 1996, and who was later mourned by both Christians and Muslims.

Cardinal Radcliffe said "pointless violence had flowered into friendship".

The congregation also heard the testimony of Ribqa Nevash, who spoke of the pressure on Christians in present-day Pakistan, saying churches had been burned and Christians had faced discrimination because of their religion.

The 25-year-old, originally from Faisalabad, said she was relieved to be in the UK where she could openly celebrate Christmas.

King Charles is known to have a great interest in Orthodox Christianity and an array of icons had been set up for the service.

There was a hymn sung in the Coptic language by the Coptic Orthodox Diocesan Choir and a carol was sung by the choir of the Syriac Orthodox Church.

There was also a 14th-Century carol, and prayers sung in Latin, which rose up in the high ceilings of the medieval Abbey.

The King's message focused on the Advent hymn, O Come, O Come, Emmanuel, and he quoted its message of hope with the line: "Dispel the long night's lingering gloom, and pierce the shadows of the tomb."

The King has a long commitment to building bridges between faiths, and the congregation also included representatives of Muslim, Jewish, Sikh and Hindu communities.

In October he visited the Vatican for a historic religious service with Pope Leo in the Sistine Chapel. (BBC)