The number of agency workers in the UK has grown to 800,000, a 40% increase over the past decade, according to research from the Resolution Foundation.

The research, which polled 500 HR managers, found that most firms using agency workers do so for traditional reasons such as filling gaps in staffing (46%) or as a last resort (19%). The Foundation also found that firms overall do not use agency workers as a cost control device, with  only 29% believing they are cheaper or more expensive than direct employees.

Meanwhile, 34% appear to be using agency workers more strategically to fill as many posts as possible or for particular parts of their workforce. Moreover, 25% say they plan to increase their use of agency workers over the next five years, and 55% expect to maintain current levels.

Despite the plans to hire more agency workers, the Resolution Foundation pointed to a more recent plateau in agency worker numbers, with no increase since 2015.

“As employee jobs with better rights become more available, and migration levels fall, firms that rely heavily on agency workers may need to rethink their business models urgently,” the research stated.

“While some firms may adjust their business models as flexible, cheap labour becomes less readily available, it is equally important that the rights of those who remain in agency work are improved,” the research stated. “Repealing the Swedish Derogation, which allows firms to pay agency workers less than directly comparable employees should be key. While the government stopped short of committing to this in its response to the Taylor Review this week, the Foundation argues that the time is ripe for action in this area.”