Tesco has been named the worst of the big four UK supermarkets at complying with a code designed to protect suppliers.

This result comes from a confidential survey of more than 1,000 supermarket suppliers conducted by YouGov on behalf of the Groceries Code Adjudicator (GCA). 30% of respondents said that Tesco rarely complied with the Grocery Supply Code of Practice and 4% said that it never complied. It was also found that 54% of all issues raised with suppliers last year were with Tesco.

In comparison, only 5% of suppliers said that Aldi rarely or never complied, 11% for Waitrose and 12% for Sainsbury's and Marks & Spencer. Morrison's did considerably worse, with 32% of suppliers saying it rarely or never complied, and only Iceland scored lower than Tesco, with a total of 35%.

Although Tesco is ranked the worst of the big four supermarkets it has done better than 2014, when a total of 41% of respondents said it rarely or never complied. Overall the results across the survey have improved, with the number of suppliers experiencing potential breaches of the code falling from 79% to 70%.

Christine Tacon, who leads the GCA, began a formal investigation into Tesco in February, believing that it had breached the supply code of practice. She has, however, said that the supermarket has seen a 'big improvement' under new chief executive Dave Lewis, who has been attempting to improve the retailer's relationship with suppliers. Commenting on the results of the survey, Ms Tacon said: 'We still have some way to go in important areas, but this is a clear sign we are on the right track. Suppliers are more aware of the GCA and its work and fewer now believe the GCA will not be able to do anything if they bring an issue to me.'

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