We are unlikely to spend our last moments regretting that we didn’t spend enough of our lives chained to a desk. We may instead find ourselves rueing the time we didn’t spend watching our children grow, or with our loved ones, or travelling, or on the cultural or leisure pursuits that bring us happiness. Alas: the average full-time British employee works 42 hours a week, well over a third of the time we are awake. Some of our all too precious time is being stolen: British workers do around two billion hours of unpaid overtime each year. So it is extremely welcome that Labour’s John McDonnell has approached eminent economist Lord Skidelsky to head an inquiry into potentially cutting the working week to four days. It should be part of a new crusade for the left: of defending and expanding personal freedom.

The champions of free market fundamentalism promised their creed would bring us freedom. But it wasn’t freedom at all: from the lack of secure, affordable housing to growing job insecurity and rising personal debt, the individual is trapped. Nine decades ago, John Maynard Keynes predicted that technological advances and rising productivity would mean that we’d be working a 15-hour week by now: that target has been somewhat missed.

Facebook Twitter Pinterest ‘It is extremely welcome that Labour’s John McDonnell (above) has approached economist Lord Skidelsky to head an inquiry into potentially cutting the working week.’ Photograph: Wiktor Szymanowicz/REX/Shutterstock

Here is the most pernicious threat to our personal freedom, particularly as the balance of power in the workplace has been shifted so dramatically from worker to boss. A huge portion of our lives involves the surrender of our freedom and personal autonomy. It is time in which we are directed by the needs and whims of others, and denied the right to make our own choices. It is bad for us: it is hardly surprising that over half a million workers suffer from work-related mental health conditions each year, or that 15.4 million working days were lost to work-related stress last year, a jump of nearly a quarter.

Yes, there are those who, far from being overworked, actually seek more hours. But a shorter working week would enable us to redistribute hours from the overworked to the underworked. Lord Skidelsky’s inquiry would need to look at cutting the working week without slashing living standards: after all, Britain’s workers have already suffered the worst squeeze in wages since the Napoleonic wars. But cutting the working week would free the individual, giving millions of workers more time to spend as they see fit. Human freedom should be the core aim of modern socialism. The right to work less would be an act of liberation – and a cause the left should embrace.

• Owen Jones is a Guardian columnist