A group of eight large UK institutional investors are stepping up their campaign against neutral, "mark-to-market" accounting standards, with a call to the House of Lords to investigate whether the most widely-used and internationally-accepted standards actually contravene UK law.

The letter represents a ramping-up of a campaign that has been in train for more than a year; ever since the House of Lords published an investigation into the role of accountants in the 2008 financial crisis, in March 2011.