An urgent appeal opposing armed intervention in Syria, made by a Damascus-based Patriarch, was heard during an all-important debate in the UK Houses of Parliament.

Speaking in the House of Lords on Thursday, Baroness Caroline Cox of Queensbury quoted Melkite Greek Catholic Patriarch Gregorios III who said that armed intervention by the West in Syria would only "fuel" violence and unrest.

The Patriarch had made his comments in an interview with Catholic charity Aid to the Church in Need, stressing that, in spite of the growing conflict, reconciliation initiatives were still viable.

Highlighting the Patriarch's concerns, Baroness Cox told the House of Lords: "I am profoundly wary about beginning a military intervention which could unleash even more suffering.

"Bringing the perpetrators of crime against humanity to justice should be our priority, not aiding and abetting militias who are committing heinous and egregious violations of human rights."

The Lords debate came on the same day as a debate in the House of Commons in which MPs rejected the government's motion proposing UK involvement in US-led strikes on Syria.

Prime Minister David Cameron's call for a military response in Syria followed reports of a chemical weapons attack on the outskirts of Damascus on 21st August, in which hundreds of people are understood to have died.

In his ACN interview, Patriarch Gregorios, who was in Damascus at about the time of the alleged chemical weapons attack, expressed scepticism, saying: "Who can know who was behind the chemical attack?

"You should not accuse the government one day and accuse the opposition the next. That is how you fuel violence and hatred."

Reflecting the Patriarch's concerns, Baroness Cox began her House of Lords speech stating: "First, may I refer to concerns expressed by [Patriarch Gregorios].

"In an interview with the highly respected Catholic charity Aid to the Church in Need, he argued that military intervention by the West against the Assad regime in Syria would be disastrous, especially as nobody can be sure who was responsible for last week's chemical weapons attack."

Baroness Cox, an author and campaigner on behalf of persecuted Christians, whom she has visited in many of the worst-affected countries, went on to highlight the suffering of Church members in Syria.

She quoted figures from Patriarch Gregorios who claims that 450,000 – nearly a third of the Syria's faithful – are either displaced within the country or have fled abroad as refugees.

Referring to how until recently Syria had been a "beacon of hope" for Christians in the region, she said there were "growing concerns that the Church's presence is being eradicated from the very place Christ and his first disciples knew as their own".

Baroness Cox also underlined the growing humanitarian crisis in Syria.

She stated that nearly 7 million people are now in need of assistance and that the numbers of internally displaced had doubled since the beginning of 2013, adding an appeal for help from organisations including CAFOD.

Patriarch Gregorios III has accepted an invitation to be guest-of-honour at Aid to the Church in Need UK's Westminster Event in central London on Saturday, 19th October 2013. It begins with Mass in Westminster Cathedral at 10.30am and continuing afterwards in the cathedral hall.

In Glasgow he will participate in an ACN event on Monday, 21st October 2013 at Christ the King Church, Kingspark beginning with Mass at 7pm with talks to follow. Visit www.acnuk.org/westminster