Tacon revealed: "The most shocking thing I found was how widespread it was and that it was in every sector and every supplier I spoke to had evidence in delays in payments.
"A Tesco list of methods for meeting the half-year target included 'Not paying back money owed'.
"The evidence I received revealed a number of examples of Tesco deliberately deferring payment of money in order to maintain its margin at key financial reporting periods.
"I find that Tesco knowingly delayed paying money to suppliers in order to improve its own financial position."
She added: "In particular, requests for payments to meet margin targets appeared to be more prevalent at the end of trading periods. Some suppliers reported that what set Tesco apart from other retailers was the pressure it put on suppliers at the end of a financial quarter, half-year or full-year."
The supermarket also avoided dealing with suppliers it was in dispute with, and Tacon pointed out "one of the key cultural factors" which caused the delays was an apparent "reluctance of some Tesco buyers to pro-actively engage in the resolution of payment disputes. There were times when Tesco did not appear to even attempt to resolve supplier concerns before unilaterally deducting money from suppliers."
Tesco boss Dave Lewis has four weeks to decide how Tesco will respond (Picture: Reuters)
Neil Hall/Reuters
Bosses were in breach of the code on payment delays, but not on charging suppliers directly for prominent positioning on shelves. However, she found that there were examples of indirect charging, which may require the code to be modified.
The GCA only recently were granted the power to fine supermarkets, but not retrospectively, meaning Tesco avoided a fine.
The report did find, however, that Tesco has subsequently improved its relations with suppliers after chief executive Dave Lewis simplified the supply chain.
