SINN FÉIN'S John Finucane has urged the international community to step up and call for 'a full, immediate ceasefire' in the fighting between Israel and Hamas.
The Belfast North MP was speaking at a pro-Palestinian demonstration in London on Saturday, which was attended by around 100,000 people.
Several hundred demonstrators also staged a sit-in protest at Waterloo Station in the capital, where they chanted 'Ceasefire now' and 'Free Palestine'.
According to the Met Police, nine people were arrested duirng Saturday's events.
The demonstration came a day after the UN General Assembly adopted a resolution calling for an 'immediate, durable and sustained humanitarian truce' between Israeli forces and Hamas militants in Gaza.
'Unimaginable pain'
Saturday's event saw protestors march from Embankment to Parliament Square, where those in attendance heard from speakers including former Labour leader Jeremy Corbyn and trade union leader Mick Lynch.
The event, organised by the Palestine Solidarity Campaign, also heard from a number of current Labour MPs, including John McDonnell, Andy McDonald, Richard Burgon and Zarah Sultana.
Mr Finucane called for nations around the world to press for an immediate ceasefire as he said the situation in Gaza was being compounded by the 'Israeli government’s desire to inflict more pain, more suffering'.
"Today we stand together in our hundreds of thousands as Gaza is being destroyed before the eyes of the world as Israel unleashes its full military might on a defenceless population," he said.
"Over 20,000 children, women and men dead or injured, more than a million Palestinians displaced, and countless homes, hospitals and schools turned to rubble.
"Day after day we hear of the horror emanating from Gaza, the unimaginable pain, suffering and death, a deliberately enforced tragedy made worse by an Israeli Government's desire to inflict more pain, more suffering."
He added: "Our message to the Israeli Government is clear and simple — stop.
"Stop the bombing of Gaza. Stop the blockade of Gaza. Stop the occupation, illegal settlements and apartheid.
"The international community must step up and call for a full, immediate ceasefire. Hostages must be returned.
"All efforts must focus on ceasefires, dialogue and a negotiations process that can deliver a just and lasting peace in the Middle East based upon the creation of a viable Palestinian state."
The Met Police said it had made seven arrests for Public Order offences during the event.
It added that a number of those arrests were being treated as hate crimes.
Two further arrests were made for assaults on police officers.
'No room for doubt'
On Friday, Ireland backed the UN's resolution calling for a ceasefire, however, Tánaiste Michael Martin expressed his frustration that an amendment condemning Hamas was not adopted.
"We are disappointed that a Canadian amendment, clearly condemning the brutal terrorist attack by Hamas and calling for the immediate and unconditional release of hostages, was not approved," said Mr Martin, the Minister for Foreign Affairs.
"There should be no room for doubt on this.
"We also recall that obligations under International Humanitarian Law fall to all parties, state and non-state actors alike."
Canada ultimately abstained on the vote, which was backed by 121 UN member states and demanded that all parties immediately and fully comply with their obligations under international law.
Britain also abstained after voting in favour of the Canadian amendment, saying it could not vote for a resolution 'that is silent on the largest terror attack in Israel's history'.