Tesco boss Dave Lewis has told Tesco’s employees they “must speak up” if they suspect misconduct in its trading relationships with suppliers.

The retailer has published details of a new Code of Business Conduct, which The Grocer first revealed was to be launched in November, in a bid to prevent a repeat of the behaviour which plunged it into crisis last year, when a £263m hole in its accounts led to a raft of senior executives being suspended.

With an investigation by the Groceries Code Adjudicator, Christine Tacon, underway, as well as the ongoing probe by the Serious Fraud Office, Lewis said he wanted all Tesco colleagues to have the confidence to come forward if they had concerns.

The new Code includes 21 different “key risk areas”, spanning from concerns over a repeat of the horsegate meat scandal, to protection of data on Clubcard and ethical trading with foreign suppliers.

However, it is the promise to provide new scrutiny of the Groceries Supply Code of Practice (GSCOP) which was perhaps the main driver of the code after the revelations of last year.

“Investigations into breaches can be costly and time-consuming,” says the document. “Significant fines may result and customer trust may be damaged.”

Tesco said it was vital that staff kept to agreements with suppliers, including not making retrospective changes, giving reasonable notice of any changes to supply agreements and being “thoughtful and empathetic” when communicating with suppliers.

The Tesco Protector Line will also enable Tesco staff to confidentially report behaviour they suspect is in breach of GSCOP or other elements of its new code.

“If you ever have concerns about you own conduct or that of another person you must speak up straight away,” said Lewis, who urged staff to use the phone line if they were unwilling to speak to their line manager, personnel managers or Tesco‘s legal team.

“Knowing our policies, applying good judgment, being honest and speaking up are just some of the ways that we can build pride in Tesco,” he added.