FTSE 250 companies’ pension shortfalls doubled to £12bn in a year by the end of June, a report shows, and would have been much higher had yields on corporate bonds not risen through the credit crunch.

The report, by Pension Capital Strategies and Cazenove, concluded that if rates on risk-free gilts had been used to discount liabilities – as used by the Pension Protection Fund insurance scheme – the shortfall would be £80bn, up from £55bn a year earlier.