A withering assessment of NHS management, by the Conservative peer Lord Stuart Rose, who is credited with turning around the fortunes of Marks & Spencer, was submitted to the Department of Health in December but has still not been published by the government.

It is understood to paint a damaging picture of a culture in which mediocre managers can move around within the NHS without being held to account, while those who are successful go unrewarded.

Lord Rose was appointed to carry out the review in February last year by Jeremy Hunt, the Health Secretary. At the time, the government said it hoped he would be able to advise on how the NHS could “attract and retain the very best leaders to help transform the culture in under-performing hospitals”.

But one person who has seen the report told the Financial Times that Lord Rose, who is now chairman of online supermarket Ocado, had found the overall standard of much NHS management to be “totally shocking”.

According to another source, the government’s response to the report has been put on “the back burner of the back burner”. The timing is particularly sensitive for the Tories, who have faced frequent attacks by Labour on the state of the NHS under the Coalition as the general election approaches.

MPs said that Lord Rose’s assessment must be made public immediately. Jamie Reed, Labour’s shadow Health Minister, told The Independent: “If the government has nothing to hide it should release the report before the election. Ministers cannot commission reports on the NHS and bury the ones they don’t like. When people vote in May, they need to have all the facts about this government’s mismanagement of the health service.”

Ukip leader Nigel Farage also wrote on Twitter: “Surely this will have to be published before the election so we can see [what] the establishment has done to our NHS?” A spokesperson for the Department of Health said the government would be publishing the report “in due course”.

Lord Rose, who is close to David Cameron, is among a group of corporate leaders who have publicly attacked Ed Miliband. The Tory peer recently described the Labour leader as having a “steady drum-beat of anti-business policies” which harked back to the 1970s.