According to the Office for National Statistics, 2.9% (903,000) of employees said they work on a zero hours basis between April and June this year.
The figure is a 20% rise on the same period last year, when 2.4% (747,000) said they were employed on the controversial terms, which do not guarantee employees a set wage.
Some (55%) of those claiming to work on zero-hours contracts are women, compared with 45% for other types of contract.
A third of zero-hours workers are aged 16-24, while one in five people employed under the terms are in full time education.
Campaigners claimed victory earlier this week after controversial firm Sports Direct announced it would abolish zero-hours contracts for directly employed, casual retail staff.