But it concludes that the international reach of some major retail chains means wider EU measures have to be considered to ensure fair play for farmers and consumers.

Development organisation Traidcraft, the NFU and EU farm organisations Boerenbond and Coldiretti, commissioned the report, by the British Institute for International and Comparative Law (BIICL), to identify how the European Union can take steps to tackle unfair commercial practices in dealings between retailers and suppliers.

The report reveals that at least 10 EU Member States have already taken steps at a national level to root out bad practice while a further five are in the process of implementing measures.

Speaking about the report, NFU Director of Corporate Affairs, Tom Hind said: "The challenges that suppliers face in dealing with abusive behaviour from supermarkets and other big businesses is not unique to British farmers but also affects those in developing countries and other parts of the EU. That's why we felt it was important to collaborate on this important research.

"The absolute priority at this stage must be to get the Groceries Code Adjudicator up and running to enforce the existing Groceries Supply Chain Code of Practice and curb the abuse that regrettably carries on here in the UK. The UK Government has to act swiftly taking a lead in the next Queen's speech on 9 May."

Fiona Gooch, policy adviser at Traidcraft, said: "It is really important that we look beyond the UK. As the food industry becomes more multinational, increasingly there will be a case for the EU to ensure some consistency and effective enforcement across all member states. Failure to act would not only have a detrimental impact on farmers across the EU and in developing countries but ultimately undermine consumer choice in the long-term."