Many workers do not fully understand their rights, the EHRC says
An inquiry into the treatment of agency and migrant staff at meat and poultry processing firms has found "widespread evidence" of abuse and exploitation.
The abuse was both verbal and physical, the Equality and Human Rights Commission reported.
It also found a lack of proper health and safety protection and said workers often did not know all their rights.
Retailers and labour providers said they would be studying the findings to see where improvements could be made.
Stories of abuse
However, the chairman of the Association of Labour Providers, Mark Boleat, was also quoted by the Guardian as questioning the inquiry's methodology and whether the surveyed workers were a representative sample.
Agnes Gnosowska, 29, is a Polish national who lives in Thetford, in Norfolk.
She has previously worked in a meat factory and says such jobs are the "only choice" for many unskilled workers from Eastern Europe, particularly those who do not speak English.
"In Eastern Europe some salaries are so low that you can't survive," she says.
So they come here, but if they don't have specific skills or speak the language then they don't have another option but to do this kind of work."
The EHRC's inquiry, launched in 2008, found that migrant workers are most affected, but British agency employees face similar mistreatment, with many people afraid to raise concerns because they fear they will be sacked.
The commission said its inquiry had uncovered frequent breaches of the law and licensing standards in meat processing factories.
Some of these factories supplied the UK's biggest supermarkets.
However, the commission, which called for steps to protect the workforce and for supermarkets to improve the auditing of their suppliers, said it had also found examples of firms that treated all workers with respect and dignity.
The inquiry, which spoke to 260 workers, found:
• One in five workers said they had been pushed, kicked or had things thrown at them by line managers
• A third revealed they had experienced or witnessed verbal abuse, often on a daily basis
• Workers also claimed they had been refused permission to go to the toilet
• One in four told the commission that pregnant workers had been mistreated, including the instant dismissal of agency workers who announced they were having a baby
A third of permanent workers and two-thirds of agency workers in the industry are migrants, and at one in six meat processing sites involved in the study, every agency worker hired in the past year was a migrant worker.
These recruitment figures are partly due to difficulties in recruiting British workers for physically demanding but low-paid work, the EHRC said.
Many workers who gave evidence to the commission said agency workers were treated worse than directly employed staff.
Neil Kinghan, director general of the EHRC, said: "The commission's inquiry reveals widespread and significant ill-treatment in the industry.
"We have heard stories of workers subjected to bullying, violence and being humiliated and degraded by being denied toilet breaks."
He said that some workers felt they had to put up with these conditions out of economic necessity, while others lacked the language skills to understand and assert their rights.
"While most supermarkets are carrying out audits of their suppliers, our evidence shows that these audits are not safeguarding workers and they clearly need to take steps to improve them.
"The processing firms themselves and the agencies supplying their workers also need to pay more than lip service to ensuring that workers are not subjected to unlawful and unethical treatment.
"If the situation does not improve over the next 12 months, the commission will consider using its regulatory powers to enforce change where necessary."
Jack Dromey, of the union Unite, said supermarkets supplied by the plants should "hang their heads in shame".
He said: "Supermarkets have driven down costs along their supply chain with tens of thousands of workers paying the price, suffering discrimination and unfair treatment.
"A two-tier labour market has been created, exploiting migrant agency workers on poorer conditions of employment and undercutting directly employed workers on better conditions of employment.
"That divides workforces and damages social cohesion in local communities."
A spokesman for the Association of Labour Providers said: "The recommendations merit careful study by government, regulators, supermarkets, labour providers and labour users.
"Some of the recommendations, such as paying workers for travelling time and engaging workers on contracts of employment rather than contracts for services, are not possible unless there is a commitment from retailers and labour users to meet such costs, and past experience suggests that this is unlikely."
Tom Ironside, from the British Retail Consortium, said it took the findings very seriously.
"The commission does recognise supermarkets are committing significant time and resources to these audits, but if there are ways to improve them, then obviously we'll be giving those careful consideration," he said.