Senior civil servants avoid scrutiny by hiding behind ministers, says Margaret Hodge

The head of Parliament's financial watchdog calls for more accountability and transparency

Britain's most senior civil servants will today be accused of hiding behind their ministerial masters to escape blame for maladministration costing the taxpayer billions of pounds in waste.

Margaret Hodge, the head of Parliament's powerful financial watchdog, will claim that civil servants are using the centuries-old convention of ministerial responsibility to make detailed scrutiny "ineffective".

And she will pledge to "reclaim" Parliament's authority to hold the executive to account by calling more senior civil servants to defend their decisions publicly in the House of Commons.

The intervention by Ms Hodge, chair of the influential Public Accounts Committee (PAC), will infuriate Sir Jeremy Heywood, the new Cabinet Secretary.

It comes after the PAC launched a high-profile battle with civil servants working for Her Majesty's Revenue and Customs (HMRC) over what they claimed was a cover-up of "sweetheart" deals with multimillion-pound businesses, including Goldman Sachs.

In one case, Ms Hodge forced HMRC's most senior lawyer to take an oath on the Bible before giving evidence because she felt she had been unable to get straight answers from him. In a speech to the think tank Policy Exchange, Ms Hodge is expected to argue that the tradition whereby civil servants are accountable to ministers and ministers are accountable to Parliament is not working.

She intends to cite the case of Theresa May, the Home Secretary, who insisted she knew nothing about Border Agency staff relaxing border checks and blaming the action of her civil servants, who were not officially accountable to Parliament. "Civil servants escape external accountability because they are protected by the convention of ministerial responsibility and they escape internal accountability because ministers are powerless to hold them to account in any meaningful way," she will say.

"The senior civil service needs to acknowledge that we live in a different world from the world in which ancient conventions could prevail. Everybody wants greater transparency and accountability."

Ms Hodge will cite the cases of large public procurement projects examined by her committee which have often run significantly over budget but can pass from one administration to another.

"Of course it's uncomfortable when we unearth gaping holes in the governance and accountability of HMRC," she will say. "Of course the Government and the civil service will get cross if we identify huge potential cost overruns on aircraft carriers. Of course they hate it when we look at the Olympics budget in its entirety and warn that they could break their own budget limits.

"But for ministers to respond by asserting that we are straying beyond our remit is frankly pathetic. And for civil servants to hide behind their ministers will simply not do."