Theresa May has been warned the humanitarian catastrophe in Aleppo has "descended into hell" and that the UK Government must take immediate action to alleviate the crisis.

During an emotional speech at PMQs on Wednesday, SNP Westminster leader Angus Robertson asked the Prime Minister what the UK and international community could do to end the suffering of the people of Syria.

In response, the Prime Minister agreed that Mr Roberston was right to bring up the issue and said the UK was working with France to bring forward emergency discussions in the UN Security Council.

Mr Roberston then said: “It’s extremely welcomed that the discussions are taking place at the United Nations and we wish success to all of those who are supporting a humanitarian solution to alleviate the crisis there.

“However, the agencies are saying that in Aleppo the situation is so bad that it is descending into hell.

"Time is absolutely of the essence. I know the Prime Minister and I are in agreement. Please can I appeal to her. Can absolutely everything be done now to alleviate the situation of the poor people of Aleppo and of Syria."

Mrs May responded by saying: "We have consistently looked at the possible solutions to see if there are other avenues we can press for.

"I think the security council debate is very important, and there’s an important message to send to Russia, that they actually use their influence with the Assad regime to stop these appalling atrocities and let humanitarian aid through."

It comes following a stark warning from the French ambassador ahead of the emergency meeting at the UN Security Council that the situation in Syria could soon become one of the “biggest massacres of civilian population since World War Two”.

The bombardment of Aleppo has escalated dramatically over recent days, with at least 45 civilians reported to have been killed on Wednesday after an artillery missile hit dozens of families as they attempted to flee the west of the city.

In pictures: Aleppo bombing Show all 14 1 /14 In pictures: Aleppo bombing In pictures: Aleppo bombing Bombing in Aleppo Smoke rises after airstrikes on the rebel-held al-Sakhour neighborhood of Aleppo, Syria April 29, 2016. Reuters In pictures: Aleppo bombing Bombing in Aleppo A Syrian family runs for cover amid the rubble of destroyed buildings following a reported air strike on the rebel-held neighbourhood of Al-Qatarji in the northern Syrian city of Aleppo, on April 29, 2016. AFP/Getty Images In pictures: Aleppo bombing Bombing in Aleppo A man reacts as he stands on blood stains at a site hit by airstrikes in the rebel held area of Aleppo's al-Fardous district, Syria, April 29, 2016. Reuters In pictures: Aleppo bombing Bombing in Aleppo The damage of the airstrikes in the rebel-held area of Aleppo on April 28 Reuters In pictures: Aleppo bombing Bombing in Aleppo The damaged the Medecins Sans Frontieres (MSF)-backed al-Quds hospital after it was hit by airstrikes, in a rebel-held area of Syria's Aleppo Reuters In pictures: Aleppo bombing Bombing in Aleppo Syrians evacuate an injured man amid the rubble of destroyed buildings following an air strike on a rebel-held of Aleppo on April 29, 2016. AFP/Getty Images In pictures: Aleppo bombing Bombing in Aleppo People inspect the damage at a site hit by airstrikes, in the rebel-held area of Aleppo's Bustan al-Qasr AP In pictures: Aleppo bombing Bombing in Aleppo A man leads a woman in tears and child out of the scene after airstrikes hit Aleppo AP In pictures: Aleppo bombing Bombing in Aleppo Civil defence members search for survivors after an airstrike at a field hospital in the rebel held area of al-Sukari district of Aleppo Reuters In pictures: Aleppo bombing Bombing in Aleppo A Syrian boy is comforted as he cries next to the body of a relative who died in a reported air strike in the rebel-held neighbourhood of al-Soukour in the northern city of Aleppo Getty Images In pictures: Aleppo bombing Bombing in Aleppo A Syrian family walks amid the rubble of destroyed buildings following a reported air strike in the Bustan al-Qasr rebel-held district of the northern Syrian city of Aleppo Getty Images In pictures: Aleppo bombing Bombing in Aleppo Syrian civil defence volunteers and rescuers remove a baby from under the rubble of a destroyed building following a reported air strike on the rebel-held neighbourhood of al-Kalasa in the northern Syrian city of Aleppo Getty Images In pictures: Aleppo bombing Bombing in Aleppo Syrians help a wounded youth following an air strike on the Fardous rebel held neighbourhood of the northern Syrian city of Aleppo Getty Images In pictures: Aleppo bombing Bombing in Aleppo Syrian civil defence volunteers evacuate people from a damaged building following a reported airstrike in the rebel-held neighbourhood of Tareeq al-Bab in the northern city of Aleppo

Following the attack, which is said to have been launched by the regime, dozens of bloodied bodies of women and children with rucksacks could be seen on the street in the Jeb al-Qubba neighbourhood where the missile struck.

Yasser Al-rahil, Syrian journalist and member of the Revolutionary Forces of Syria media office, told The Independent civilians in besieged Aleppo were giving up hope. He said: “People in besieged Aleppo have nothing. It’s like they are waiting to die.

"Now the city is running out of fuel, so the emergency services has had to stop their work. Houses have been destroyed so people have no homes.