It is easy to dismiss byelections as one-off events. Even with a loss on the scale of the defeat in Crewe and Nantwich, the tendency is to dismiss the result as midterm blues. In truth, the reality is more brutal: the ‘Tory toff’ campaign picked the wrong target. The public do feel that politicians are out of touch – but it is the political class, not the upper class, that is the problem.

Parliament’s greatest strength has always been its ability to draw upon the rich tapestry of people’s own lives and experiences, whatever their social class. The Labour party, born out of the union movement, brought manual workers and tradesmen to Westminster to speak to the struggles of everyday life. Teachers, social workers and miners joined their ranks, making the case for social justice in Britain as it went through vast change and upheaval. Across the House, doctors, lawyers and businessmen have brought knowledge and personal experience to the big questions of the day.

Yet as politics itself has become a profession, we have lost much of that authenticity and experience. A new political class has emerged that people struggle to identify with – and think does not identify with them. People are not stupid, they see through the tactics of political positioning and triangulation. They know when politicians are trying to manage them, rather than listen to them. They are put off, not impressed by the managerialist language of the Westminster bubble. In short, they know that too much of the political establishment, by which I mean all political parties, sees the public as ‘them’ rather than ‘us’.

The Labour party must fight at every turn to avoid becoming part of the establishment. More than ever, we need to break open politics beyond the usual suspects, bringing in people who have different experience to bring to bear on the big questions facing modern Britain. Over the last few years, there have been more attempts to draw on the views of people outside of Westminster, including new forms of public consultation. But the real breakthrough will come when Westminster itself looks and feels different as well.

If we ever needed proof of this we need only look at the impact of having more women in parliament over the last decade. Parliament itself has become more family-friendly; flexible working, maternity and paternity leave have all risen up the agenda, affordable childcare has become a priority. These are issues which strike at the heart of inequality in this country, they make real differences to people’s everyday lives and they owe their prominence to a new set of perspectives in parliament. It is a shame that Tamsin Dunwoody, herself an excellent candidate, will not be joining those ranks.

As I spoke to people in Crewe this week, many were clear what they wanted from their politicians. What we need in politics is not caricatures of class, but a discussion led by people who understand one another and the realities of people’s lives, even if they disagree on everything else. All political parties have the urge to win, but they also carry the responsibility to uphold faith in politics itself. In the end, personal attacks serve neither purpose. As a party we must be true to traditions of solidarity among people of all backgrounds, if we are to make sure that Crewe and Nantwich really was a one-off.