As work in the UK gets more precarious and the gig economy booms, trade unionism is being reimagined and people from a wide range of backgrounds are joining new kinds of unions, often for the first time.

In our new Guardian documentary, United Voices, film-maker Hazel Falck explores grassroots trade unionism through the inspiring story of a group of outsourced workers fighting for – and winning – equal rights with NHS staff, across five UK hospitals.

Filmed over the course of a year, even before Covid-19 put key workers in the spotlight, Falck documents the lives of hospital cleaners, caterers and porters on the frontline.

What inspired you to make this film?

I am always interested to know how things actually change. How does it happen, practically speaking? And how do people make that change happen? So I was interested to learn about new forms of unions and how they were finding renewed relevance as our lives and the way we work changes so quickly.

As work becomes more precarious, fragmented, and often isolated, does that make organising and collective action more likely, or more difficult? While facing economic inequality and division as we do in the UK, is collectivism even possible? What does it take to come together, to take a personal risk for a collective gain?

When I came across United Voices of the World, I found it inspiring to witness this big community working to support each other, facing challenges, taking on big cases – and winning! The St Mary’s group that we follow in the film won the Living Wage and contractual sick pay, and were brought in-house as NHS employees. This victory benefited not just themselves, but changed things for the entire outsourced workforce across five hospitals of the NHS Imperial Healthcare Trust.

It felt like a bright light of potential. I wanted more people to be inspired by that, to see that many people from different backgrounds were coming together and leading industrial action that was improving working conditions and pay for entire workforces. I set about to make a film that follows the process step by step, from the inside out, so that people could see that change is possible.

It is incredibly moving to see this group of people come together to support each other and demand change. What surprised you most about this grassroots union?

Many members of the union are from countries where resistance, collective action, and revolution are implicitly understood and part of the culture. Trade unionism is strong in the Carribean, in South America– this is an amazing influence on the situation in the UK. The St Mary’s group won the Living Wage and contractual sick pay not just for themselves, but for all the other employees across the five hospitals in the contract.

Also, I didn’t realise how varied the union was in terms of vocation, not limited to a particular sector or trade, like more traditional unions. Members of United Voices of the World are cleaners, chefs, security guards, porters, sex workers, legal sector workers, cultural sector workers, charity sector workers – a whole mix of people from different professions, cultural backgrounds, with different languages, and experiences, both at work and with union organising.

With so many members and so many challenges to face, how did you find the stories and contributors that you follow in the film?

In the first few months, many different groups and cases came to the fore – there was such an amazing energy of possibility, and it was all moving very fast. The St Mary’s case came together just as we were in the early stages of filming. We were captivated by the jeopardy of it as it was unfolding and it gained momentum quickly.

Meeting Loreta and Vitalija was quite a pivotal moment and I knew they would be a strong focus of the film. They had such tenacity and were unwavering. They had a clear sense of justice and were driven to lead the group into the strike, despite all the intimidation, doubt, and fear.

It is moving to see Loreta and Vitalija, as well as other union members, grow in confidence through the course of the film. What was your most memorable filming day?

Definitely the first strike day at St Mary’s. We left the house with Vitalija at 5.30am, and the suspense en route to the picket line was intense. We had no idea how many people would show up. In the weeks leading up to the action, there had been other contract workers brought in to undermine the strike– a method of intimidation to sow fear and doubt – so it felt really fragile.

We arrived at the hospital and everyone was there, it was so energising. Then the sun broke through the clouds and everyone was full of joy, dancing in the sun, I couldn’t wipe the smile off my face. It wasn’t like that for the rest of the shoot, it was a rollercoaster that got harder, angrier, rainier – but that first day was just a blessed day to start off with.

You shot this film before the coronavirus outbreak, but it resonates so strongly with our current context and especially the conversation around key workers and their value in today’s society.

There are millions of people working in exploitative, unsupportive, and unjust conditions in this country – in schools, hospitals, prisons, universities, and government departments that keep this country functioning. I think that coronavirus just revealed what has long been broken, it showed whom we rely on the most but seem to value the least.

The experiences of key workers illuminated the discrimination in our system. For instance, hospital cleaners, porters and social care workers were excluded from the bereavement scheme granting indefinite leave to remain to relatives of foreign national NHS staff who die from Covid-19, until workers and trade unions called out the discrimination. It has shown how far we have to go and how much needs to change to properly appreciate, pay and protect people for the valuable work they do for us all.

Join a livestreamed discussion with the film’s director, Hazel Falck and Guardian writer and documentary maker John Harris as they explore the filmmaking process and address wider questions around the themes raised in the film. During this event, you will also have the opportunity to ask your own questions to the panel in real-time.

Event date: Tuesday 25 August, 7pm-8pm BST. Click here to sign up.

United Voices is a Guardian Documentary made with the support of the Joseph Rowntree Foundation. The Joseph Rowntree Foundation is an independent social change organisation working to solve UK poverty.

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