The boss of the taxpayer-backed Royal Bank of Scotland refused today to support proposals to ringfence different banking operations and warned that the move could create more risk in the industry. RBS chief executive Stephen Hester was being grilled over plans detailed by the Independent Commission on Banking (ICB) to separate the retail arms of UK banks from the riskier investment banking divisions. Mr Hester told the Treasury Select Committee he could not give \"black and white answers\" when asked if he backed the move, and warned: \"Creating a ringfence increases some of the systemic risk and decreases the ability of banks to withstand the risk and has significant costs.\" But Mr Hester was joined in giving evidence by HSBC chairman Douglas Flint, who said a ringfence was required - although he would prefer it if there was not one. Elsewhere, Mr Hester also conceded there could have been some \"leakage\" from taxpayer support into the bonus pool. The Government commissioned the ICB report, which will be published in full in September, to review ways of avoiding \"too big to fail\" banks sparking another credit crisis.