Workers in London could be leaving around 31 million days of paid holidays unused every year, according to new research.

Employees in the capital ended their last working year with an average of 7.2 days of paid leave still in their calendars, putting London joint-third across the UK.

Truro in Cornwall came in first place, as workers averaged 7.8 unused days, while Newcastle upon Tyne followed in second place with 7.5 unused days. London was level with Cambridge and Belfast on 7.2 days.

Applying the London average to the capital’s 4.3 million pay-rolled employees would give a rough estimate of around a 31 million unused paid holiday days a year.

Dr Reem Hasan, Chief Medical Officer at Vista Health and and NHS GP, said: “Summer is often associated with rest and relaxation, but for many people it brings a very different reality.

“School holidays, juggling childcare, caring responsibilities, travel, financial pressures and covering for colleagues can all make it harder to prioritise our own health and wellbeing.

“One thing remains true throughout the seasons; your health should never be put on hold. Symptoms do not wait until life becomes less busy.

“Listening to your body, seeking advice when something does not feel right and making prevention part of everyday life are some of the most important investments you can make in your future health.”

The findings come against the backdrop of one of the country’s largest labour markets, with London supporting around 6.4 million jobs, while its £618 billion economy accounts for 22.7% of UK GDP, according to City Hall, underlining the scale of working life in the capital.

Yet the Vista Health research suggests many workers are finding it difficult to step away from their jobs even when they have leave available or are feeling unwell.

Nearly a quarter of those in the UK who had unused annual leave said they had simply been too busy at work to take it (23%), while almost one in five (18%) had nobody available to cover them. Another 14% also said they worried about work piling up and didn't dare take a day off.

The poll of 2,000 people, commissioned by Vista Health also found nearly half (49%) of workers carried on working while feeling sick this summer for an average of six days.

Almost three in 10 (28%) said they did so because they had too much work to do, while 19% did not want to lose pay.

Others believed they could power through their illness (18%), had nobody available to cover them (17%) or feared their workload would pile up (16%).

But continuing to work while ill came at a cost, with 28% becoming less productive, a quarter (25%) struggling to concentrate and almost a quarter (24%) feeling worse by the end of the day.

Summer health problems were also widespread, with nearly half (45%) having trouble sleeping, while 32% struggled with stress or anxiety and 31% suffered extreme tiredness or fatigue.

The research also found three in 10 Brits (29%) had also put off a health appointment, test or check during the summer - postponing it for an average of six weeks.

Work was the biggest obstacle, with 35% saying they had been too busy with their job.

Others could not get a convenient appointment (15%) or did not believe the problem was serious enough (15%).

Delaying care was already affecting some respondents, with a quarter (25%) becoming more worried or anxious, 21% suffering disrupted sleep and 20% saying their symptoms were lasting longer.

The pressures could now follow people into the new season, with half of Brits (50%) worried they will head into autumn already feeling tired or run down.