Theresa May has been accused of jeopardising the government's "pro-business" agenda because of the slow pace of slashing red tape at the Home Office.
Tory business minister Michael Fallon and Lib Dem business secretary Vince Cable sent the home secretary a "scathing letter" warning her that the Home Office's progress was a "risk" to the government's deregulation efforts, the Financial Times reported.
This government spat is not the first time Fallon and May have been at odds; in June the business minister stirred rumours that the home secretary had "leadership ambitions".
Asked if he could persuade May to buy more British cars at the Home Office as "it might even help her leadership ambitions", Fallon responded to gasps: "They may not need that much help."
Coalition ministers have pledged to leave office having reduced the overall burden of regulation. However, May has shied away from cutting red tape in areas like the UK Border Agency for fear that it could open up weaknesses in the immigration system.
A Home Office spokesperson said: "We have addressed specific crimes that are problematic for business – like metal theft. Legitimate colleges and universities have benefited from the regulations we introduced to tackle the bogus colleges that used to sell immigration, not education."