Mouchel was locked in talks to avoid breaching a banking covenant following a £4.3m accounting blunder that led to a profits warning and the hasty departure of Richard Cuthbert, its chief executive.

The outsourcer has overestimated the profits from one contract by £4.3m because of an actuarial error on pensions liabilities inherited from a local authority contract. Sources close to the company said it was considering legal action against the actuaries.