The care sector has the highest number of night shift workers in the UK, with 437,000 employees, according to new research.
This is followed by nurses and midwives (232,000) and road transport drivers (208,000), the Trades Union Congress has found.
Across Britain, there are now 3.25 million night workers, 100,000 more than five years ago, according to the Office of National Statistics.
This means that front-line care professionals account for 13% of all night shift workers in the country.
Broken down by gender, there are 341,000 female care workers contributing to the night-time economy, compared to 96,0000 male care workers.
Overall, there are now nearly one million (924,000) night workers aged over 50 – up from 751,000 five years ago. A significant proportion are aged over 60 (222,000) and 65 (69,000).
The TUC cited older employers staying in work for longer and more jobs being created in sectors like social care as the reasons for this.
The South East has the most night workers in Britain (435,000) with London close behind (414,000).
But the North East (14.8%), Scotland (13.3%), Wales (13%) and Midlands (13%) have higher shares of their workforce regularly doing night work than the capital (11%).
The TUC is now urging greater protection for the millions of UK workers who regularly work through the night.
Nigel Costley, regional secretary of TUC South West Nigel Costleysaid: “Britain’s loyal army of night workers has been boosted significantly by older workers. We all owe them a huge debt for keeping the country ticking over while we are asleep.
“However, working nights can be really tough – it can disrupt family life and place a strain on people’s health and their pockets with costs soaring due to limited public transport or childcare services.”
“Night workers can also be subject to damaging insecure work contracts and low pay.
“This government is not doing enough to protect night workers. They need better notice of night shifts and proper compensation to account for the increased costs of night working.”