Charity confederation Oxfam has alleged that workers on farms and plantations that supply some big supermarket chains are being subjected to human rights abuses.

It claims new research reveals that poverty pay, harsh working conditions, and gender discrimination are commonplace on the farms that supply fruit and vegetables to companies such as Lidl, PLUS, and Whole Foods.

Oxfam conducted interviews with workers countries including the U.S., India, Brazil, Costa Rica, Ecuador, Peru, and the Philippines.

It says that retailers’ "relentless" drive to cut costs and maximize profits is fuelling poverty and abuse in their supply chains.

“Supermarkets are snapping up the lion’s share of the price we pay at the till - while workers who toil for hours to grow and harvest tea, fruit and vegetables are paid so little they can’t even feed their own families," said Winnie Byanyima, executive director of Oxfam International.

Researchers said they found evidence in North East Brazil of poverty among harvest workers on grape, melon and mango farms.  

Workers also reported developing allergies and serious skin diseases as a result of working with pesticides and other chemicals without adequate protection, it claimed.

The farms reportedly supply Lidl, Sainsbury's, and Whole Foods and, until recently, Morrisons, PLUS and Tesco, according to Oxfam. Walmart and Kroger have neither denied nor confirmed links, it added.

Three-quarters of workers questioned in a new survey said that they were not paid enough to cover basic needs such as food and housing.

And over a third said they were not protected from injury or harm at work and were not able to take a toilet break or have a drink of water when they needed it.

Supermarkets 'taking a bigger share of the price'

Oxfam also said that supermarkets are taking an ever-increasing share of the price paid by shoppers.

In the U.S., supermarkets and tea brands capture almost 94% of the price of a pack of black tea with less than 1% accruing to workers on tea estates.

In the UK, supermarket and tea brands receive 49p, and workers collectively receive just three pence, from a pack of black tea selling for 74p, according to Oxfam.

“Supermarkets must open up about where they buy their products from and they must ensure that their buying practices are not fuelling poverty and abuse, that workers in their supply chains are paid a living wage and have safe and dignified working conditions; and that women workers are free from discrimination,” Byanyima said.