When Nadia Whittome was growing up, her mother told her that, as a working-class girl of colour, she had to be twice as good as others to be judged half as good. Evidently, it was a lesson that the youngest MP to enter parliament at after last month’s general election took to heart. After all, not every 23-year-old’s nights out clubbing end with them trying diligently to unionise the staff. “Sometimes in the club toilets there are women selling deodorants or sweets. And I’ll go up to them and have a chat and just get to know them and ask whether they’re in a union,” explains the new Labour MP for Nottingham East, grinning. “My friends are always like: ‘Nadia, we’re going to get the shots in ...’ But politics is life, isn’t it? We live it every day.”

She is living it very differently these days, however. Almost overnight, Whittome went from living at home with her mum in Nottingham to representing her city in parliament and being grilled on the Today programme. Her election victory was a light on an otherwise dark night for the radical left. But it is a lot to take in for someone selected only 24 hours before the election was called and who had never lived away from home before she was elected (although she now has a flat in London for weeknights, she is still under her mother’s roof in her constituency). “People keep asking me how I feel, and the truth is there’s no time to process how I feel. I’m just getting on with the job,” she says. “It does feel really odd that, not very long ago, I was looking for Christmas temp work – got rejected from a lot of Christmas temp work – and now I’m a member of parliament.”

The so-called baby of the house has a certain steel about her. “I don’t want to start to feel comfortable in that place,” she says of parliament. “I’m not here to become part of the fabric of Westminster; I’m here to change it.”

If she seems unusually self-possessed for her age, perhaps it is because Whittome had to grow up faster than some. She turned to activism as a teenager, she says, after watching friends on her estate struggle to cope under Tory austerity measures. Before long, this daughter of immigrants – her mother, who raised her as a single parent, is British-Indian; her father is of Punjabi heritage – was protesting against the bedroom tax alongside Tony Benn and organising with Deliveroo riders against gig economy working practices.

Facebook Twitter Pinterest ‘The individual policies of the manifesto were popular, but we hadn’t built support’ ... Nadia Whittome (bottom left) on the campaign trail in Nottingham with Jeremy Corbyn. Photograph: Joe Giddens/PA Wire

Whittome says she joined Labour under Ed Miliband because she wanted it to be an anti-austerity party; in 2015, she was an early cheerleader for Jeremy Corbyn’s campaign to succeed him. Having run unsuccessfully for a local council seat, she beat stiff competition to be selected as the party’s candidate for the safe seat of Nottingham East after the incumbent Labour MP, the Corbyn critic Chris Leslie, defected to the short-lived Independent Group for Change. Whittome had been the official candidate for a day when Boris Johnson called the 2019 election.

Whittome is from a politically engaged family: her grandparents belonged to the Communist party of India (which she stresses is different from the Communist party in Britain) and her mother quit the Labour party over the decision to amend clause IV in 1995. “I get a lot of my strength from my mum, but also the networks that we built around us,” says Whittome.

Her mother is a social-care lawyer working in local government; she got her law degree as a mature student and was out of work for five years when Whittome and her brother were young. Originally, Whittome planned to become a lawyer, too – partly due to the feeling that “I have got to provide for my family when my mother can’t” – but she dropped out of university after two years for financial reasons.

That must have been tough, I say. But she insists she loved the jobs she got instead, as a care worker and a hate-crime project worker. “When I first stood for election, I was asked by people – white, middle-class academics: ‘When are you going to get a proper job?’ And I’d say: ‘I’ve got a proper job; I’m a care worker.’ It felt like a real privilege to be let into people’s homes and facilitate their lives. For a lot of people, you’re the only person they see all day.” She snorts at the argument that young people need more real-life experience before becoming MPs, pointing out that age is no guarantee of that: “Jacob Rees-Mogg is in his 50s and he’s never changed a nappy.”

Yet it is undeniably a steep learning curve, moving from anonymous activist with the freedom to say what you like to this merciless public stage. Whittome has already triggered a kerfuffle by tweeting, when Iain Duncan Smith was knighted, that she was “thinking of the millions of people whose loved ones have been killed” by his policies. Does she really believe welfare reform directly claimed millions, or even hundreds of thousands, of lives?

What should have been a climate election was taken over by Brexit

“Millions isn’t necessarily an overestimation,” she says. “There were, in 2017, 130,000 people who died avoidably due to austerity.” But the study I think she is citing, which examined the years 2012 to 2017, was not about welfare policy – it was about higher-than-expected numbers of deaths, which the authors suggested (but could not prove) reflected cuts in health spending. What evidence has she for this serious accusation against the former work and pensions secretary? “Specifically on welfare policies, we don’t know how many people have died as a result of universal credit. We know that people have died due to austerity.” All right, but that is not what she tweeted.

However, Whittome’s convictions are not easily shaken. “The bigger problem is that we are talking about ‘Is it tens of thousands, is it hundreds of thousands?’ – it’s certainly not dozens – and ‘How many people do each of these people know?’, to ascertain exactly how many people are mourning and how many people have died. The fact that we’re having this conversation in the media, rather than actually dealing with the immediate issue, is sad.” To Whittome, all this is splitting hairs, yet she is operating in a world where precision matters.

Of course, Whittome is not the first new MP to walk a tightrope between the formal demands of public life and staying true to his or her roots. (She has swapped numbers with the SNP MP Mhairi Black, who was only 20 when she was elected in 2015; they plan to compare notes over a drink.) But she is clearly anxious not to cut herself off from her community, which is why she promised to take home only £35,000 of her £79,468 salary and give the rest to local causes and strike funds. Her sacrifice may not have endeared her to Labour colleagues, who will be bracing themselves to justify taking their full pay. But Whittome says she did not mean to imply that politicians do not deserve the money; she just thinks that firefighters and teaching assistants deserve a rise, too – and she will take hers only when they get theirs. So is this purely a personal decision, or does she think other MPs should follow suit? “It’s a personal decision. I think it’s an important representative principle, because as Labour MPs we are workers’ representatives. I certainly don’t berate MPs for taking the full salary.”

Yet for all her determination to “rise with her class, not above it”, Whittome recognises that in some senses she has already changed. “As much as I was a working-class woman on 12 December, now I’m not,” she says. “I walk the corridors of power and I have huge responsibility to share that [power] with everyone else.”

On election night, Whittome tweeted about wanting to be “a new kind of MP”, inspired by radical women of colour. Those inspirations range from “the Squad” in the US – the hotshot progressive Democrats Alexandra Ocasio-Cortez, Ilhan Omar, Ayanna Pressley and Rashida Tlaib – to the late factory worker Jayaben Desai, who led the 1976 strike at the Grunwick film processing plant in north-west London. She feels particularly connected to Desai, who challenged lazy assumptions about female Indian workers: “People thought that she was a docile, subservient Asian woman and she was anything but.”

Facebook Twitter Pinterest ‘I walk the corridors of power and I have huge responsibility to share that power’ ... Whittome on ITV’s Peston with the Tory MP Tom Tugendhat and the Green MP Caroline Lucas. Photograph: Jonathan Hordle/Rex/Shutterstock

Whittome is under no illusions about what she may face in the current political climate. The day after the Brexit referendum, she was called an “effing black bitch” on the street in what is now her constituency. She does not consider the timing a coincidence. “I wasn’t the only person I know who suffered intensified abuse after Brexit,” she says. “I think Nigel Farage and Boris Johnson’s campaigns, which had very clear and overt racist undertones, legitimised the racism that already existed.” There is every chance that the abusive passerby is one of her constituents, while the man she sees as legitimising hate runs the country.

The lesson she takes from Corbyn’s crushing defeat last month is not that the party was too leftwing or too pro-remain, but that it didn’t make its case early enough, either for a second Brexit referendum or for policies such as free broadband. “The individual policies of the manifesto were popular, but there were just so many of them and we hadn’t built support,” Whittome says. She is passionate about tackling the climate crisis and would rather have seen the promise of 1m new green jobs take centre stage: “I think what should have been a climate election was taken over by a Brexit election.”

Whittome nominated Clive Lewis to replace Corbyn as Labour leader – Lewis dropped out last week after failing to get enough nominations from Labour MPs and MEPs – and Dawn Butler for deputy. It worries her that BAME candidates such as Lewis, Butler and Rosena Allin-Khan had to plead for help getting on the ballot, while Lisa Nandy initially lagged behind the frontrunners; she remembers wanting to back Rushanara Ali for deputy in 2015 and not getting the chance because Ali could not get enough nominations. Why does she think this keeps happening? She says she has faith in her parliamentary colleagues, but adds: “I think we need to interrogate our unconscious biases … we’re lawmakers, and it’s our responsibility to interrogate our privilege and to use the immense power that we have to amplify the voices of people who don’t get heard.”

She is concerned, too, about calls for Labour to win back white, working-class voters by taking a tougher line on issues such as immigration. “That’s why I wanted Clive on the ballot. I don’t want to be back in a PLP [parliamentary Labour party] meeting in five years’ time, talking about losing and winning back our heartlands, but we are talking now about different heartlands: Brixton, Nottingham, Liverpool.” Her city seat is a traditional Labour stronghold, she points out, but one with many more black voters than the towns where Labour lost. “I want to hear from candidates and activists in those places about what needs to change. But I’m also clear that we can’t just follow the conversation with immigration – we need to lead it, too. We need to make arguments for immigrants that aren’t just about people’s economic value, because the continuation of that is: when they are no longer of any economic value, they’re not welcome here.”

The generational divide on the left between those comfortable with so-called identity politics and those occasionally confounded by it feels very clear talking to Whittome. Her politics is intersectional, deftly navigating the prickly places where race, class and other sources of discrimination collide; she expresses sympathy with the Duchess of Sussex’s battle for acceptance in Britain, but she adds that liberation is not only about women at the top: “Even if all the top business leaders were women of colour, that wouldn’t make one jot of difference while lower-paid women of colour were being paid less than £10 an hour for cleaning on zero-hours contracts.”

Yet this wariness of privilege in any form may not always sit easily with acquiring political power. When a cabbie asked recently if this was her dream job, she hesitated: “I thought: ‘Actually, I don’t think my generation dreams the way that the older generation really did.’ Our dreams are a lot more short-term: they’re things like moving out of the family home, getting a job – any job, really. These are the struggles that occupy a lot of our thinking. That and the fact that we won’t have a planet to live on if we don’t take drastic action. That’s my experience growing up in Nottingham – that we don’t live in a society where we can afford to dream.” Whittome can dream bigger now, but it may take her a while to get used to that.

• This article was amended on 22 January 2020 to clarify that the sum of £35,000 which Whittome is planning to take is after tax. The basic annual salary for an MP before tax is £79,468.