Royal Bank of Scotland has been forced to defend its practice of holding unminuted dinners before board meetings during the financial crisis.

The lender is locked in a legal dispute with investors who claim they were misled into taking part in its £12bn cash call just months before the bank, which was helmed by disgraced former chief executive Fred Goodwin, succumbed to a £46bn bailout.

Three groups of shareholders settled with the state-backed bank last week but two other claimants, including the RBS Shareholder Action Group, which represents 27,000 retail investors, rejected the £800m offer made by the lender.

It means the bank and Mr Goodwin still face the prospect of going to court in March.