John Varley, former chief executive of Barclays, has been pushed to explain why the bank paid Qatari investors £280m in fees as part of its emergency cash call during the 2008 financial crisis.

In testy exchanges with the legal team for PCP Capital Partners, the private equity firm run by Amanda Staveley, Varley described the fees as a “sensible commercial bet” based on the premise that the bank could secure a lucrative, lasting relationship with the Gulf state.