NEW figures on zero hours contracts are predicted to show they are being increasingly used by employers.
The Resolution Foundation said the scale of the contracts, under which workers do not know how many hours they will work from one week to the next, presents a challenge to Prime Minister Theresa May after she pledged to tackle job insecurity.
Research by the think tank showed that more than two out of three adult contract workers have been on one for over a year.
New official figures are today expected to show an increase in the use of zero hours contracts over the past year, said the foundation.
While the contracts make up a small share of the labour market - less than a million workers are on one - they form part of a wider growth of atypical employment, including self-employment and agency work, which often lack the rights and security that employees receive, said the report.
The foundation argued that the flexibility provided to some workers means a blanket ban would be counter-productive, but it argued that the Prime Minister should introduce further protections for workers who have been on a zero hours contract for over a year and work regular hours.
The analysis follows the move by Sports Direct to offer directly employed staff on zero hours contracts guaranteed hours of work.
Conor D'Arcy, policy analyst at the Resolution Foundation, said: "For some, zero hours contracts are symbolic of Britain's job-creating labour market flexibility, while for others they represent the deep insecurity that belies the recent jobs recovery.
"The fact that the use of zero hours contracts has grown - and the Prime Minister has chosen to highlight the issue of job insecurity in her maiden speech - mean that they need far closer, and more measured, scrutiny.
"Banning zero hours contracts outright is a misguided approach that risks penalising those workers, such as some students and those with caring responsibilities, who genuinely prefer the flexibility afforded by them.
"But many workers who are on them want more stability, reliable hours and greater protection. Helping them get this should be a priority of this government."
