Public Accounts Committee scrutinising civil servants
4 September 2012 Last updated at 10:40 BST
MPs who sit on select committees in the House of Commons have the power to haul officials, ministers and almost anyone they like before them to answer questions.
The Public Accounts Committee (PAC) stands out as the one to regularly name and shame departments it believes are guilty of wasting public money, and is known as a committee that scares the Sir Humphreys of Whitehall.
David Thompson spoke to constitutional historian Lord Hennessy and PAC member Stewart Jackson MP on its work bringing top civil servants to account.