The number of workers on zero-hours contracts has increased by more than 100,000 over the past 12 months.
The Office for National Statistics said the figure had breached 801,000 – the highest since records began.
The figure represents 2.5% of the UK workforce, up from 2.3% in the same period of 2014.
Nick Palmer, statistician at the ONS, said: “This latest figure is rather higher than the 697,000 people who said they were on these contracts in late 2014. Though at least some of this increase may be due to greater public recognition of the term ‘zero-hours contract’, there’s also nothing to suggest this form of employment is in decline.”
People on zero-hours contracts were more likely to be young, part time, women, or in full-time education when compared with other people in employment. It said on average a worker on a zero-hours contract usually worked around 26 hours a week.
Around one in three people (37%) on a zero-hours contract wanted more hours. The ONS said most of these wanted more hours in their current job, as opposed to a different job which offered more hours, while just 10% of other people in employment wanted more hours.
In November 2015 there were around 1.7 million contracts that did not guarantee a minimum number of hours where some work had recently been carried out, according to the latest ONS survey of businesses.
For May 2015 the equivalent estimate was 2.1 million, though the ONS said some of the difference between May and November could be caused by seasonal factors.