The number of people in the UK whose main job is based on a zero-hours contract reached 905,000 last year for the quarter ended December 2016, up 13% from the same period last year, according to figures from the Office of National Statistics.

The ONS figures, taken from a Labour Force Survey, showed that the 905,000 people on zero-hours contracts in their main job, represented 2.8% of all people in employment.

However, the total number of zero-hours contracts in total, including those who use a zero hours contract to supplement their main job was 1.7 million at the end of 2017, which represented 6% of all employment contracts and was unchanged from the same period last year.

ONS states that there is no single agreed definition of what “zero-hours contracts” are and that, while some contracts are explicitly called zero-hours contracts, there are other definitions available and used in published statistics. The common element to the definitions is the lack of a guaranteed minimum number of hours.

According to ONS, people on “zero-hours contracts” are more likely to be young, part-time, women, or in full-time education when compared with other people in employment. On average, someone on a “zero-hours contract” usually works 25 hours a week. Around one in three people (32%) on a “zero-hours contract” want more hours, with most wanting them in their current job, as opposed to a different job which offers more hours. In comparison 9% of other people in employment wanted more hours.