“Unfortunately, the current process set out in the Ministerial Code, where officials carry out costings based on assumptions provided by Special Advisers, is now putting HM Treasury officials in an impossible position.” Letter from Ed Balls, January 4 2015

“The Labour Party is today publishing a factual account of the cost of a Conservative government based on the Conservative Party’s own figures and analysis from publicly available figures, such as costings from HM Treasury.” Dossier issued by Alistair Darling, January 4 2010

(See also here.)