The boss of the UK’s biggest independent co-operative has hit back at Lord Myners over his attack on him and other Co-op board members.

Midcounties Co-operative chief executive Ben Reid told The Guardian it was “tragic” that Myners personally vilified the Co-op’s directors for the governance failures at the group.

Myners was drafted in to review the group’s structure after it was hit by scandals including the near-collapse of its bank.

When unveiling his report on Wednesday, he said it was “astonishing” that Reid was still on the group’s board after sitting on the Co-op Bank’s audit committee for three years while a £1.5bn hole built up in its finances.

Myners also alleged that some directors did not know the difference between a credit and a debit.

Reid said: “It’s a shame that the debate has got personal when it’s about something more important than Ben Reid or Paul Myners. We’ve got the AGM next week and I look forward to us having a good debate and moving forward.”  

“I’m not the only one that has been on the board in that time. There are all sorts of implications of what Paul is saying. Why he would target me I don’t know.”

Reid and other independent co-operatives will play a pivotal role in determining whether the reforms that Myners is proposing for the Co-op Group are voted through next Saturday. Independent Co-operatives own 22% of the group, with representatives of its 8 million members controlling the rest.

The Midcounties Co-operative that Reid presides over has been vocal in its criticism of the reform proposals in the past. In April, president of the Midcounties Co-operative Patrick Gray said his board unanimously decided not to back the ideas as they stood.

Under Myners’ proposals, the board, which is made up of Reid, fellow independent society bosses and 15 member representatives, would be replaced by a board of experienced directors. A separate membership council would oversee the new boardroom and ensure co-operative values are maintained.

In March, Reid defended the co-operative business model and said it should not stray from the mutual model or add layers of authority that distance the group from its members.

However, Reid told The Guardian he is open to change.

Representatives will vote on Myners’ proposals at the group AGM next Saturday.