The number of people on zero-hour contracts as their main job has risen by more than 100,000 to nearly 700,000 according to official new figures from the ONS.
The Office for National Statistics said the number of people estimated to be employed on a zero-hours contact in their main job was 697,000, an increase from 586,000 from the same period in 2013. The number of people in this situation represents 2.3% of all people in employment, up from 1.9% in 2013.
The total number of employment contracts offering no minimum hours jumped from 1.4m in 2013 to 1.8m in 2014, due to workers often having more than one job.
The 28% increase is due to more increasing recognition of the contracts by staff when asked by researchers about their employment terms, rather than the result of a surge in the number of zero-hour contacts offered by employers last year the ONS said.
The ONS said over half of businesses in the hotel and catering sectors used the contracts and a quarter of businesses in education made some use of no-guaranteed-hours contracts in August 2014, with universities and colleges becoming large-scale users of zero-hours contracts, while an estimated 160,000 care staff are also on similar deals.
The ONS added around a third of people on zero hour contracts want more hours, remarking that people on zero-hours deals are more likely to be women, students in full-time education or working part-time. They are also more likely to be aged under 25, or 65 and over.
The business secretary Vince Cable said some criticism of employers who offer these contracts was valid, especially those that put exclusivity clauses in the contracts, preventing workers from holding more than one job. A ban on exclusivity clauses is being suggested through parliament at the moment.
But the business secretary added that the contracts “are valued by many employers and individuals who want flexibility in the hours they work”, naming students, people with caring responsibilities, and those who want to partially retire as beneficiaries.
The ONS added that its consecutive surveys of total contracts were also difficult to compare because they were carried out at different times of the year and prone to seasonal changes in employment practices.