Idea is to refer chemical weapons issue to UN general assembly, where Russia’s security council veto would not apply.

Western nations want to end the months-long paralysis at the United Nations over Syria by referring the issue of chemical weapons use to the entire UN general assembly, where Russia’s security council veto would not apply.

The idea is to draw on a rarely used route first established in the cold war to transfer responsibility for aspects of the crisis to the 193-member general assembly.

Russia has used its security council veto powers 11 times to block action targeting its ally Syria. A UN mechanism to attribute responsibility for chemical weapons use came to an end in November after Russia vetoed a resolution to extend its mandate, complaining that the mechanism was prejudiced against the Syrian government.

Ian Martin, a former UN official and Amnesty International chief, said: “The Russian veto need not be the end of efforts for collective action by the UN. The responsibility of asserting accountability for the use of chemical weapons, and for bringing an end to the horrors of the Syrian conflict, rests with the world community as a whole.”

The proposal is known to have support among western officials.

The impasse was raised at an annual weekend closed-door retreat attended by security council ambassadors in Sweden, and is now likely to be discussed further at a series of meetings this week. Western powers fear the absence of an attribution mechanism not only gives Syria free range to continue to use chemical weapons, but also to deliver a severe blow to the international world order.

The US, France and the UK launched a missile attack on Syria’s alleged chemical weapons sites 10 days ago in response to allegations that the Syrian government used chemical weapons in an attack on the town of Douma on 7 April.

Inspectors from the Organisation for the Prohibition of Chemical Weapons are in Douma. But regardless of what they find, the OPCW does not have powers to attribute responsibility.

Since that strike there have been renewed diplomatic efforts, largely brokered by Sweden, to agree a UN resolution on a new investigatory mechanism, but so far they have been fruitless.

Western governments, worried that the impasse is weakening the wider authority of the security council, want to pick up a rarely used route, first set up in the 1950 Korean crisis. Called “uniting for peace”, it would enable nine members of the 15-strong security council to bypass a Russian veto and refer the matter to a full vote at the general assembly. It would then require a two-thirds majority by the general assembly for an attribution mechanism to be agreed.

The 1950 “uniting for peace” route was explicitly designed to be used when the security council could not meet its responsibilities over maintenance of peace.

The UN secretary general, António Guterres, said at the weekend that the world had entered a new cold war era where the threat of instability was greater than the previous cold war.

In objecting to an attribution mechanism, Russia has opposed the mix of nationalities on the OPCW and the absence of routine on-site inspections. It also insists that final decisions on attribution must be made by the security council, where it can wield its veto.

The western powers have made concessions to secure a compromise UN resolution on attribution, but will not concede the principle that Russian could veto the inspection team findings.

A separate proposal for Guterres to set up special panel on Syria, as has happened in the past over Sri Lanka, has been greeted with scepticism because it would be easy for Russia to dismiss such an ad hoc body set up on the sole authority of the secretary general.

The western missile strikes appears to have had little impact on either side, making concessions in the Syrian peace talks.

A meeting of G7 foreign ministers in Canada agreed that Russia needed to do more to contribute to a political settlement in Syria, but the UN special envoy, Staffan de Mistura, met Russian officials over the weekend in Moscow, and little evidence emerged that Russia was willing to force the Syrian president, Bashar al-Assad, to negotiate with opposition groups on a future constitution.

An EU humanitarian conference in Brussels on Tuesday and Wednesday is likely to focus on how to prepare for an expected Syrian regime attack on Idlib, in north-west Syria, one of the last remaining rebel held areas in the country.