The conditions set by Ed Miliband, above, for a strike on Syria appear to be more tightly defined than those outlined by Jim Murphy. Photograph: Toby Melville/Reuters
Ed Miliband has hardened his position over Syria by saying that Labour would only support military action against the Assad regime if Britain’s national security was threatened or al-Qaida and its affiliates gained possession of large stockpiles of chemical weapons.
In a significant toughening of its stance, the Labour leadership has decided there would have to be a “very significant change” in circumstances to allow Britain to join any operation in Syria.
The move comes amid growing criticism among frontbenchers and other Labour MPs about Miliband’s handling of Syria. During the runup to the votes in parliament last week, the Labour leader said he was seeking to secure a proper legal and political underpinning to justify British military involvement after the chemical weapons attack on 21 August.
Labour made clear last week that it accepted the attack justified a military response if a definitive link could be established to the Assad regime, if action was deemed lawful and if the UN was properly consulted.
Party sources admitted that Miliband is now raising the bar because the attack east of Damascus that prompted the recall of parliament would not have met his new conditions. But they say Miliband is having to work in different circumstances after the prime minister declared following his defeat last Thursday that Britain would not take part in any military action.
A senior Labour source said: “There would need to be very significant change [for Labour to support military action]. There are two examples: if al-Qaida got possession of very large stockpiles of weapons or if there is a direct threat to national security.
“The political reality is that the prime minister has said Britain will not take part in military action. Everyone is having to work within that context.”
The fresh conditions set by Miliband appear to be more tightly defined than those outlined by the shadow defence secretary, Jim Murphy. In a blog on Sunday, in which he said he supported “a conditions-based approach” to military intervention, Murphy wrote: “A policy of indefinite inaction regardless of what happens in Syria or at the UN would be unwise. An attack on an ally by Assad or further chemical atrocities would give the PM a right to bring this back to parliament. But he cannot just re-run last week’s vote and hope for a different result.”
One Labour source said the conditions should also include an atrocity that is defined as a crime against humanity. The Arab League has declared that the attack on 21 August was such a crime.
Labour sources said Murphy, who wrote in his blog that he agreed with every word Miliband said in parliament last week, was at one with the Labour leader. His blog was aimed at George Osborne and William Hague hours after they ruled out British military involvement in Syria.
Philip Hammond, the defence secretary, told Murphy that Britain would not be involved in military action unless circumstances “change very significantly”. Hammond said: “If I may say so, it is a bit rich for [Jim Murphy], who last week trooped into the lobby behind the leader of his party, giving rise to the very situation in which we now find ourselves, to demand that I tell him precisely in which circumstances we might revisit this issue.”
Senior Labour figures are voicing concerns in private. One MP said: “What a mess. I don’t think any of the frontbenchers know how to get out of this one. I’m sure our great leader knows what he was doing.”
Another MP said: “I am very worried that this could lead us to a position where Britain is not able to mount a military response if needed. We cannot have situation where Britain just retreats into humanitarian-only response.”
The unease about Miliband, which follows the voicing in private of concerns by Tory ministers of David Cameron’s failure to sense the mood among his MPs, is being expressed with great care by frontbenchers. They acknowledge that the overwhelming number of Labour MPs are highly wary of military action in the light of the party’s experience over Iraq.
But some frontbenchers have raised doubts about Miliband’s decision to instruct his MPs to vote against the government motion, ensuring its defeat, because this has made it all but impossible to see how Britain could countenance military action even if conditions in Syria deteriorate.