Speaking at an evidence gathering session for the Future of Work inquiry being conducted by the Business, Energy and Industrial Strategy parliamentary select committee Steve Turner, assistant general secretary at the Unite Union said that his union had predominantly come across the "criminal and dodgy" agencies that existed to exploit the workforce.

Some companies are changing their business model and increasingly employing agency staff and in some cases avoid paying national insurance contributions to cut their costs Turner claimed.

Although Turner accepted there were responsible agencies the ones that were exploitative were operating in every sector of the economy. He also suggested that there are now around 1.6million workers in the UK in some kind of agency role or casally employed larger than the approximately 865,000 suggested by the government's official figures.

He said that taking on casual workers was a business model choice by the companies although it also exists within the public sector too within health, care and education. Businesses like this, Turner said, do not see the employee as core to their business any longer.

For the agency workers themselves they had lost control of their employment because the agencies had the control. The companies meanwhile had an unfair competitive advantage over responsible employers who were paying better wages and investing in their staff, Turner suggested.

Turner said trade unions were adapting to the changing work place. He suggested that some agencies and companies were hostile to even allowing them access to workers and the employees were then fearful of approaching a trade union. He said, particularly with migrant workers, Unite was organising them in their communities to ensure they had fair employee rights.

In an earlier hearing Hannah Reed, Senior Employment Rights Officer at the TUC said its research showed that nearly one in 10 workers in the UK were at risk of losing out on basic rights in the workplace. That means that they are often vulnerable to mistreatment in the workplace.