On a freezing cold day in the winter of 2012 I was driving around an English inner city with the chief executive of a small voluntary organisation who was explaining how the area she worked in – one of longstanding deprivation with well above average levels of child poverty – had seen some improvements prior to 2010 thanks in part to cash injections from government neighbourhood renewal programmes. There were physical indicators of development such as well maintained public spaces and also less visible (but no less vital) proof of how government grants had helped to cultivate projects, including the youth services run by her organisation with the help of local volunteers. She was immensely proud of what had been achieved.

When the conversation moved on to what was happening under the government's unprecedented austerity programme, she choked up. She asked not to be put on camera for her interview: "because I will cry".

This was a person with a long and accomplished career in the voluntary sector, who had worked with people in poverty for many years. Tough times were nothing new to her. But the fact that the community organisation she was running had to terminate some of its most effective services and lay off staff owing to cuts in government grants was clearly getting to her.

"It's different this time," she said of the government's austerity masterplan. "It's deliberate. We are doing the best we can, making what we have stretch as far as possible, but I'm not sure how much longer we can keep doing that."

By the time David Cameron stood up in London at a lord mayor's banquet in front of the financial elites in November 2013 and ostensibly admitted (from an ornate golden throne, no less) that austerity was not an emergency response to testing economic times after all, but a permanent disassembling of the state, neither longstanding critics nor the people at the sharp end of three and a half years of cuts were surprised. Bombastic and buoyed by the recent news of an economic upturn, Cameron revealed his true colours. He talked of forging "a leaner, more efficient state", and uttered the words many felt he had been holding back since 2010, when he claimed that he was imposing cuts out of necessity.

"We need to do more with less. Not just now, but permanently," he said. There it was – a declaration of permanent austerity. It was the dream even Margaret Thatcher hadn't dared to dream.

As I travelled across the UK in 2012 and 2013 conducting interviews with people living with the effects of austerity and examining the ways in which it has scarred individuals, families and communities, I encountered a kind of anger and resistance. These weren't people going on marches or waving placards or joining campaigns. These were people working on the front line or silently existing, who, when someone finally put a microphone in front of them and sought their opinion, grasped the opportunity, because otherwise they were too busy day-to-day coping, caring and providing, to speak out. But they were still ardent in their opposition. They could see what was happening to themselves, their neighbours and their communities and were crying out for a voice.

Many had constructive ideas to put forward for how things could be improved, and many were adamant that if things did not change for the better soon – especially for young people – serious episodes of social unrest like the riots of 2011, where hundreds of people primarily from disadvantaged areas took to the streets during days of violence and looting, could happen again. As one person in Birmingham told me: "All it will take is one long, hot summer."

In Glasgow, David Martin expressed the views of a number of interviewees: "We have the bankers' pay rises of millions and the super rich's cut in tax rates. This seems to the people on the street [as] the government looking after its own. People are angry at this and I think if things keep going the way they have been and the anger rises there may very well be people out on the streets."

What the myriad opposition to austerity represented was something much bigger than the sum of its parts. The groups and individuals speaking out held up a moral mirror to the politicians who were the architects of austerity, and to those in society who remained silent or complicit as injustice grew. Most importantly, they were a reminder, with each interview, each campus upset, each arrest, each petition and each wheelchair chained to another, that the belts being tightened were not those of the rich but of the poorest, most marginalised and most vulnerable in society. We were not all in this together. We never were. And if austerity was to be allowed to become a permanent fixture of the British state, then what was at stake was that we never would be.

If there was one overriding message from the journey I made around "Austerity UK", it was this: people are only prepared to take so much. The women I interviewed in Croxteth, Liverpool, such as Debbie, a local community worker, were resolutely of this view. "If Mr Cameron thinks he's getting away with this he's got another thing coming," she said. "It may take people to hit rock bottom, but we'll fight him. We'll end up fighting him – definitely. We can't constantly let him do that to us. We are good people. We're nice people. We want our children to have the best. We bring our children up with good values. None of us is lazy. If he thinks he's getting away with it he's not. End of."

When I go into deprived communities and talk to people who are struggling, it feels almost like going home. I don't have to put myself in their shoes because those were my shoes until, at the age of 18, I escaped "the poverty trap" thanks in part to outstanding teachers and visionary schools that taught my fellow pupils and myself that we had as much right to aspiration and achievement as people from wealthier backgrounds. I was the first person from my family to go to university, and the first in my inner-city comprehensive to get to Oxbridge. Because of this it matters deeply to me that young people from disadvantaged backgrounds are given opportunities on an equal footing with their wealthier counterparts.

It matters to me that current and future generations of poor children are not relegated to the margins of society and made to feel that they or their families are skivers – as was so vigorously being preached by "austerians" and neoliberal elites in Austerity UK.

When I was 10, my father, a 36-year-old bricklayer who had worked every day since he left school at 14, became unemployed due to health difficulties within the family. Despite our family's misfortune, thanks to the welfare state I was able to live in a home fit to be lived in because we were provided with a council house that meant we had basic amenities like an indoor toilet and bathroom. Thanks to the welfare state I had libraries to go to and a nutritious free meal at school every day. I had free eye tests and a subsidised school uniform. I was able to fulfil my potential because the welfare state provided me with some of the essentials in life. It gave me a fighting chance.

What is so rarely understood – and what has been under direct attack during austerity – is that the welfare state is not about dependency: it is about opportunity. Done well, it is a life raft when times are tough and a springboard to better things.

The social safety net envisaged at the end of the second world war, and supported and upheld by successive governments over many decades, was designed for that purpose. It was a potent signal that we had moved on from less enlightened times, and that fairness and justice had a central place in our government and our society.

I consider myself to be a graduate of the welfare state – and I am proud of it. I know the crippling shame of poverty and what it feels like to internalise that shame, but I also know the liberation of moving beyond it and, therefore, why supporting those less fortunate within our society is not just desirable, but necessary. We all do better if our poorest citizens do better – it is the most fundamental riposte to neoliberal individualism and to austerity.

In the course of researching and writing my book and observing the impact of the systematic dismantling of the welfare state, I have become more convinced than ever of its importance, its nobility and its role as a force for good. Yes, it could be improved. Yes, it needs to adapt. But to lose it? That would be an indictment of us all, and an inexcusable betrayal of future generations.

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