Most shift workers receive less than a week’s notice of their working hours, new figures suggest.
Research by the Living Wage Foundation (LWF) found the issue was most acute in London.
A survey of 2,000 adults showed 37% of all UK workers in full or part-time employment were given less than a week’s notice of their shift or work patterns.
Among those polled whose jobs involved variable hours or shift work, the proportion rose to 62%.
The figures suggested that 12% of the shift workers, or 7% of all adults, had less than 24 hours’ notice of work.
Work notice periods of less than a week were particularly common in London, affecting 48% of all workers, followed by Scotland (35%), the south of England excluding London (34%) and the north of England (33%).
A further survey of 2,000 adults by the LWF found that among those working full-time and paid below its definition of a "real living wage" – £10.85 per hour in London and £9.50 elsewhere in the UK – 55% had less than a week’s notice and 15% less than 24 hours.
Low-paid full-time workers from black, Asian and minority ethnic backgrounds were also disproportionately affected, as were workers with children, the figures showed.
Laura Gardiner, director of the LWF, said: "Without clear notice of shift patterns provided in good time, millions of workers have had to make impossible choices on childcare, transport and other important aspects of family life.
"Low-paid workers have been particularly hard hit during the pandemic, with millions struggling to plan their lives due to the double whammy of changing restrictions on economic activity and insufficient notice of work schedules from employers."
TUC general secretary Frances O’Grady said: "No-one should have their shifts cancelled without proper notice and compensation.
"And it’s not right to ask staff to work longer days to make up their hours.
"People need to be treated with dignity and respect at work."