THERE will be no British involvement in a missile strike against the Syrian government, after MPs voted against a military response to the use of chemical weapons in the country's civil war.

After a debate on Thursday, MPs rejected the motion endorsing the use of force "if necessary" by 285 votes to 272. Among those voting against the motion were 30 Conservative MPs.

In a parallel debate in the House of Lords, the Archbishop of Canterbury questioned whether alternative courses of action had been exhausted.

During his speech setting out the case for action, the Prime Minister suggested that "the well of public opinion was well and truly poisoned by the Iraq episode". But, he argued, the situation in Syria was "fundamentally different". Referring to the horrors of a suspected chemical attack in Damascus last week (News, 29 August), he set out Britain's duty to "uphold that international taboo against the use of chemical weapons".

After quoting from a letter from the Joint Intelligence Committee ("It is not possible for the opposition to have carried out a chemical weapons attack on this scale"), Mr Cameron conceded that no intelligence existed to "convince me that I am right and anyone who disagrees with me is wrong". But he argued: "We all have to reach a judgement about what happened and who was responsible. . . and the intelligence that I have reported - is enough to conclude that the regime is responsible and should be held accountable."

The Labour leader, Ed Miliband, called for "compelling evidence that the Syrian regime was responsible for the attack", demanding that the Prime Minister "must make a better case" for military action. Parliament should devote "time and space to scrutinise what is being proposed by the Government, to see what the implications are".

Having lost the vote at 10 p.m., at the end of a debate of more than seven hours, Mr Cameron said: "I strongly believe in the need for a tough response to the use of chemical weapons but I also believe in respecting the will of the House of Commons. It is clear to me that the British Parliament, reflecting the views of the British people, does not want to see British military action. I get that, and the Government will act accordingly."

Last night, the defence secretary, Philip Hammond, confirmed that Britain would not take military action in Syria.

In a speech in the House of Lords, before the Commons voted, the Archbishop of Canterbury noted: "There is as much risk in inaction as there is in action"; but he suggested that the Just War theory taught: "The step of opening fire is one that must only be taken when there is no possible alternative whatsoever, under any circumstances."

He was among several peers who warned of the consequences of intervention for Christians in the Middle East. A "very senior Christian leader in the region" had told him on Wednesday that "intervention from abroad will declare open season on the Christian communities".

He warned: "If we take action that diminishes the chance of peace and reconciliation, when inevitably a political solution has to be found, whether it's near term or in the long-term future, then we will have contributed to more killing, and this war will be deeply unjust."

A C of E briefing paper sent to peers before the debate rehearsed the Just War criteria for action. In the section about the need for a reasonable chance of success, it states: "The Middle East is both angry and frightened at present. It is also bitterly divided and increasingly violent. To lunch Cruise missiles into this volatile situation is to to invite the unforeseeable and for the unwanted to make its explosive appearance."

Baroness Cox quoted the Melkite Greek Catholic Church Patriarch of Antioch, Gregorios III, who last week escaped a bomb blast in Damascus. He had described the threat of Western military intervention as "a tragedy - for the whole country and the whole Middle East". He had also highlighted a "growing concern that Christianity is being eradicated from the very place Christ and his first disciples once knew as their own".

Concerns about the plight of Christians were also raised in the House of Commons. Dr Liam Fox, a former defence secretary, warned: "To exchange an Iran-friendly and Hezbollah-friendly Assad regime for an anti-West, anti-Christian, and anti-Israel al-Qaeda regime does not seem to offer us any advantage."

Before the vote, Syrian clergy had spoken out against military intervention (News, 29 August), calling instead for a political solution to the crisis.

On Friday, the General Bishop of the Coptic Orthodox Church in the United Kingdom, Bishop Angaelos, wrote on Twitter: "Thankful for UKParliament decision on Syria. World does not need another war! Now we can start thinking how to really help Syrian people."

Janet Symes, Middle East head at Christian Aid, also welcomed the vote. "We are really pleased with the outcome, particularly because of the consideration that was given to the humanitarian consequences of military action," she said on Friday.

"Our view is that peaceful alternatives have not been exhausted. . . One of the angles we have been thinking through, is how the British Government can assist the different parties in the conflict to be able to engage in reconciliation and negotation. . .

"Not taking military action does not mean that we are saying yes to impunity, or that we are saying no to action. . . The British Government is in an excellent position to be able to lead and engage with others in the international community, to bring alternatives to the fore."

In Parliament's search for alternatives to military intervention, bishops did not escape notice. In the House of Lords, the cross-bench peer Lord Thomas of Swynnerton suggested that "churchmen" be included in a delegation sent to negotiate with President Assad. "That might inspire the Syrian leaders to realise that at least we are capable of novelty, if nothing else."