The demand comes amid mounting concern at the situation in war torn Syria.
In the latest development, the UN's Syria envoy said that if confirmed, reports of a chlorine attack in Aleppo would constitute a "war crime."
On Friday, there was no letup in fighting between Syrian allied forces backed by Russian airstrikes and rebels in Aleppo on Thursday, a day after reports of a chlorine attack on rebel positions.
The Organisation for the Prohibition of Chemical Weapons said Thursday the reports of possible chemical weapons use in Syria were "of great concern."
Opposing sides in the conflict have accused each other of using chlorine gas throughout the war.
Since early July, an estimated 250,000 to 275,000 civilians have been cut off from humanitarian aid due to shifting front lines in the war in Syria.
Spanish MEP Enrique Guerrero Salom has now warned that if humanitarian corridors are not restored immediately “then hundreds of thousands of lives are at risk.”
The S&D group is now calling on all parties to enable “unconditional, unimpeded and sustained access for humanitarian groups as soon as possible.”
Salom, a Vice-Chair of the Socialist group in the European Parliament and his party’s spokesperson for humanitarian aid, said, “We need to see an immediate cease to hostilities to ensure that humanitarian aid can get to the places where it is needed most.
“The basic human rights of hundreds of thousands of people are under severe threat. Protection must be guaranteed to all those trapped in Aleppo based on the principles of neutrality and impartiality.”
He added, “A weekly 48-hour humanitarian pause would allow humanitarian groups to get the necessary supplies to those in need.
“The suffering of civilians cannot be used for political leverage, the Security Council and the international community must work with greater urgency to bring an end to the hostilities.”
Further comment came from Elena Valenciano, another S&D MEP and Chair of Parliament's subcommittee on human rights.
The Spanish MEP said, “The situation in Aleppo has deteriorated gravely over the last month. The attacks on hospitals, schools and other civilian infrastructure must stop. All sides must respect basic human rights and international humanitarian law. If we do not act immediately, hundreds of thousands of people are at risk of starvation and disease.”
She went on, “Those wounded in the war and those with serious illnesses most be treated as a priority.
“All parties to the conflict must respect the rules of war and international humanitarian law. The international community must make re-establishing access its overwhelming priority to prevent more needless loss of life.”
Meanwhile, citing the current humanitarian conditions across Syria, the United Nations Emergency Relief Coordinator has urged fresh momentum and action to protect civilians and ensure sustained aid access “before it's too late,” including through the establishment of a weekly, 48-hour pause of the fighting in eastern Aleppo, where food supplies are expected to run out next month.
“The international community has shown unity of purpose before and must show it again, before it's too late and we face the prospect of losing another generation of Syrians to conflict and misery,” said Stephen O'Brien, who is also the Under-Secretary-General for Humanitarian Affairs.
He stressed the importance of rebuilding the momentum created in the first half of the year, in particular by the humanitarian task force of the International Syria Support Group (ISSG) - consisting of the UN, the Arab League, the European Union and 18 countries that have been working on a way forward since late last year.