Originally published in Guardian Sustainable Business food hub.

“What is 60 dirhams [£4 a day] going to do for your livelihood?” asks Lahcen, a tomato picker in Morocco. His response is clear: “it’s nothing”. Yet, that is all he is reported to earn a day working in hazardous conditions in tomato fields. He relies on credit to buy groceries for his family and other necessities like medicine are an out of reach luxury.

Lahcen’s story is one of many that serve as a reminder of the hidden costs of the food we eat. While agriculture can lift communities out of poverty, many agricultural workers live on scarce incomes. There is a bitter irony in the vulnerability of the people who produce our food not being able to afford their own.

In recent months discount chains have knocked major European supermarkets off the top spot and their share prices have tumbled to a new low, fuelling a price war on key grocery items. Supermarkets are feeling the squeeze and this is resonating through their supply chains. But as the price of many consumers’ shopping baskets falls, it is important this does not come at the cost of human rights.

In a recent report, Fairfood International raised concerns that tomato suppliers to European supermarkets, including Tesco, Sainsbury’s and Dutch supermarket Ahold, do not provide a living wage to workers on their fields. When Business & Human Rights Resource Centre brought these concerns to the companies’ attention, all three said that they paid at least the minimum wage and had existing commitments to improving working conditions in their supply chain. Tesco and Sainsbury’s undertook separate investigations into their Moroccan tomato suppliers and are in discussions with Fairfood about workers’ wages.

The responsibility of businesses to respect human rights is clearly outlined in the UN Guiding Principles on Business and Human Rights. In order to fulfil this responsibility, businesses must exercise human rights due diligence, which includes integrating human rights into their governance and management systems, undertaking rigorous human rights impact assessments, providing access to remedy for victims, and reporting on their human rights performance.

The active engagement of companies like Tesco and Sainsbury’s goes some way to ensure they live up to their responsibility to respect human rights, as outlined in the UN Guiding Principles. For companies that want to lead in this space, there are a number of resources available to understand and act on their responsibility to respect human rights, including multi-stakeholder groups such as the Ethical Trading Initiative and the recently formed UK Stronger Together to tackle labour exploitation.

As consumers become more aware of the impact of their purchases and vote with their wallets, companies are realising that respect for human rights makes business sense.

Oxfam’s Behind the Brands campaign recently released an updated ranking of the 10 biggest food and beverage companies in the world on social and environmental issues, noting that they are improving. After two years of campaigns and active engagement, Unilever and Nestlé came out on top scoring the highest on average while Oxfam commended other companies such as Kellogg’s and General Mills for new commitments they have made on climate change.

However, challenges to the protection of human rights continue both at home and abroad. At Business & Human Rights Resource Centre, we continue to see reports of abuses on a daily basis, many of them in the food and agriculture industry. Some of these stories make it to mass media, such as the Guardian’s recent exposé of forced labour in Thailand’s fish industry, but many remain under-the-radar. So, as European supermarkets continue to fight for their economic survival, they must undertake due diligence throughout their supply chain to ensure their struggle to the top doesn’t become a race to the bottom for human rights.