27/02/2017 11:01 GMT | Updated 28/02/2018 05:12 GMT

How A Trafalgar Square Screening Of 'The Salesman' Morphed Into A Celebration Of Our Differences

Neil Hall / Reuters

Yesterday ten thousand Londoners from all faiths, nationalities and backgrounds came together in Trafalgar Square to watch The Salesman - the incredibly powerful exploration of revenge and forgiveness from the award-winning Iranian film director, Asghar Farhadi - followed by a performance by Damon Albarn and the Orchestra of Syrian Musicians. The event was organised by London's film community and the Mayor of London, Sadiq Khan, in solidarity with Farhadi who had vowed not to attend the Oscars, even if he was given special dispensation, in protest to Trump's "travel ban". As an Iranian national, he has been affected by President Donald Trump's executive order which seeks to ban people from seven Muslim majority countries from entering the USA.

A few hours later, across the Atlantic, Farhadi won best foreign language film (for the second time) for The Salesman. Iran's first person in space, Anousheh Ansari, read out a statement from Farhadi at the podium: "My absence is out of respect for the people of my country, and those of the other six nations who have been disrespected by the inhumane law that bans entry of immigrants to the US." The winners of best short film, The White Helmets, a film about the Nobel Peace Prize-nominated Syrian rescue group, were also noticeably absent: the 21-year-old Syrian cinematographer Khaled Khateeb was denied entry to the US to come to the Academy Awards despite having a US visa. Raed Saleh, the leader of the "White Helmets" group, chose not to come because of the escalation of the violence in Syria. "He does life-saving work and he decided his time was better [spent] by staying there" the film's director Orlando von Eisiedel said.

When news of the travel ban broke, the producer Kate Wilson and the filmmaker Mark Donne started organising the screening of The Salesman as a gesture of peaceful protest, with support from much of London's film community: Julie Christie, Keira Knightley, Terry Gilliam, Ridley Scott, Noomi Rapace, Mike Leigh and myself to name a few. The original idea was to host the event outside the US Embassy in London, however I had recently read the Mayor of London Sadiq Khan's condemnation of the ban and so immediately thought of him. On learning of our plans, Mr Khan immediately stepped in and invited us to show the film in Trafalgar Square as a celebration of London's diversity and creativity.

"While every country has the right to set its own immigration policies, this new policy flies in the face of the values of freedom and tolerance that the USA was built upon," Khan said in his statement about the travel ban. "The USA has a proud history of welcoming and resettling refugees. The President can't just turn his back on this global crisis - all countries need to play their part."

What was envisaged originally to be a protest morphed into more than that: it became instead a positive celebration. Instead of holding placards decrying what is wrong, thousands of people huddled together - for three hours, in spite of February's cold weather and moments of soft rain - to show a positive political alternative. We demonstrated a solution by celebrating our differences. By celebrating our city's commitment to tolerance and diversity.

Award-winning director Mike Leigh, Sadiq Khan and I were among those who addressed the crowds before playing this powerful video message from Farhadi: "I am extremely happy that the scattered reactions from people and art communities across the globe shown to the oppressive travel ban of immigrants has developed into a powerful and unified movement. I hope this movement will continue and spread for it has within itself the power to stand up to fascism, be victorious in the face of extremism and say no to oppressive political powers everywhere. Despite our different religions, nationalities and cultures we are all citizens of the world and I will endeavour to protect and spread this unity."

There is a lot still at stake. It is a precarious political moment. Attempts may yet still be made to discriminate against people based on where they are born, or the religion they are (directly or indirectly) associated with. We must continue, as citizens who disagree with those attempts, to take actions that refuse to discriminate against people based on their country of origin, or indeed their religion. We must continue to celebrate and draw attention to the alternative possibilities of openness and understanding.

I recently made a short film about the grassroots response to the refugee crisis in Greece and met some of the extraordinary people who are testament to the fact that compassion is a possible and appropriate response to our collective crises. In fearful political times, we must not begin to discriminate against people based on where they were born, we must not confuse a whole religion with extremism, we must not mistake a refugee for a terrorist: indeed we must not forget that many refugees are fleeing the same threat that we in the west so deeply fear.

As Asghar Farhadi puts it, whilst there are hardliners who are trying to turn people's "differences into disagreements, their disagreements into enmities and their enmities into fears", it's more vital than ever that individuals play an active role protecting and championing the spirit of openness that our city and our Mayor invited us to celebrate last night.