Ministers will come under pressure on Tuesday to help rescue civilians from the bombarded Syrian city of Aleppo. This comes after UN secretary general Ban Ki-moon raised concerns over reports of "atrocities against a large number of civilians, including women and children".
Ban stressed that civilians must be protected and aimed his remarks particularly at the Syrian government and its allies.
Former Cabinet minister Andrew Mitchell will press the Government and international community to do more to alleviate the suffering of those trapped, as Syrian president Bashar Assad's forces and Russian allies attempt to complete the process of ousting rebels.
Mitchell has secured an emergency debate on the humanitarian crisis and will urge the UK to use its "immense diplomatic muscle" to help secure a ceasefire in the besieged Syrian city.
Commons Speaker John Bercow granted him the debate, which will see ministers forced to respond in Parliament.
The debate was granted shortly after Defence Secretary Sir Michael Fallon warned it was "almost impossible" to use air drops to get aid into the city while Russia controlled the air defences in Syria.
Mitchell said: "The debate would enable us to explore with the Government how Britain's immense diplomatic muscle, the finest foreign service in the world, can do more to secure a deal that will ensure a ceasefire for at least 24 hours to enable innocent civilians to be rescued from the hideous circumstances which now prevail in east Aleppo."
He cited reports that sarin and chlorine gas have been used in the city, which would constitute a war crime, as evidence of the need for immediate action. He likened the situation to Stalingrad at the end of its destruction.
Foreign Secretary Boris Johnson has described the situation in Aleppo as "dire" and demanded that the Assad regime and its backers allow humanitarian access.
The International Committee of the Red Cross warned that thousands of civilians' lives were at risk as they have "literally nowhere safe to run".
Marianne Gasser, the organisation's head of delegation in Aleppo, said: "We stand ready to oversee the implementation of any mutual agreement that puts civilians first. We cannot urge this strongly enough: this must happen now."