“Will no one rid me of this turbulent priest?” The frustration expressed more than eight centuries ago by King Henry II of England, in a cry that inspired four knights to murder Thomas à Becket, the Archbishop of Canterbury, has been all too recognisable in UK company boardrooms in the last two years, as directors strive to manage their companies through the financial crisis and ensuing recession.

Top of the list of turbulent items has in many cases been the company-sponsored pension scheme, the value of whose assets and liabilities, reported in the company's financial statements, has been tossed about by market falls and changing interest rates.