The Chancellor of the Exchequer asked the National Audit Office to audit two new assumptions underlying the Treasury's fiscal projections within the 2009 Budget (HC 407, session 2008-09, ISBN 9780102959161). Firstly, to assess if the 2008 Pre-Budget report assumption for the trend rate of growth, allowing for a downward adjustment to the trend output level of around 4 per cent, for the post-2006 period, together with the further downward adjustment at Budget 2009 to the trend output level of around 1 per cent, is reasonable and cautious. Secondly, to examine whether the approach used by the Treasury to produce estimates of the fiscal aggregates adjusted for the effects of the economic cycle is reasonable.

This report by the National Audit Office, made under sections 156 and 157 of the Finance Act 1998, examines the conventions and assumptions underlying the Treasury's fiscal projections within the 2006 Budget (HCP 968, session 2005-06; ISBN 0102937311).

This report examines the conventions and assumptions underlying the fiscal projections within the 2010 Budget (HC 451, session 2009-10, ISBN 9780102964639) that are submitted by the Treasury for examination, along with a review of assumptions on the VAT gap, tobacco revenues, factor shares in national income and funding (debt increase)

This report by the National Audit Office, made under sections 156 and 157 of the Finance Act 1998, examines the conventions and assumptions underlying the Treasury's fiscal projections within the 2008 Budget (HC 388, session 2007-8, ISBN 9780102953336)

This report by the National Audit Office, made under sections 156 and 157 of the Finance Act 1998, examines the conventions and assumptions underlying the Treasury's fiscal projections within the 2007 Budget (HCP 342, session 2006-07; ISBN 9780102944556).