Umbrella companies: What are they?
MPs have revealed they are to investigate the role of so-called umbrella companies after many workers told BBC News they had lost out on thousands of pounds a year in wages.
The Business Select Committee says it will examine whether workers have been exploited.
It is estimated that 430,000 people in the UK are paid through such firms which act as a third party between a contractor and an employee.
The Freelance and Contractor Association said umbrella firms were an efficient way to pay temporary workers.