Tesco is to provide new training for all staff on responsible trading, in the wake of the scandal over the £263m black hole in its accounts.

The supermarket giant has published plans for a revamped Code of Business Conduct, which it said would “sit at the heart of the business.”

The code will be launched in the New Year and Tesco said it would “promote an open and honest culture within the business” and “reinforce the behaviours we expect all Tesco colleagues to follow “

It said it would set up training across the entire group as well as launching a “code intranet” to provide staff with a guide to key policies on responsible trading.

“In recent months the way we trade and operate has come under particular scrutiny, following an overstatement of our expected profits for the first half of this year,” Tesco said in a half year update on its Corporate Responsibility plans.

“As our chief executive immediately made clear, this is a serious issue which is why we launched an urgent independent investigation, led by Deloitte, to work out what happened. We have now updated the markets on the progress of this investigation and we will continue to work with the regulatory authorities to get to the bottom of exactly what went wrong.”

Lewis revealed last month that the retailer aimed to clear up any uncertainty in Tesco’s commercial teams over what practices it encouraged. The Serious Fraud Office is currently investigating the over-reporting which has led to eight of Tesco’s senior team, including UK MD Chris Bush and commercial director John Scouler being suspended.

“We have written down very clearly the judgments we want our commercial teams to make,” Lewis said. “If it’s been a grey area we will be taking the ambiguity and applying the clarity from a Tesco point of view.”