Midland MPs are on a collision course with the Home Secretary after warning they could reject her controversial appointment of a commercial lawyer as the police watchdog.

Home Secretary Theresa May has named the former rail regulator Tom Winsor as its preferred candidate to be chief inspector of the 43 police forces in England and Wales – even though he has never been a police officer himself.

He beat rival candidates including Chris Sims, the current Chief Constable of West Midlands Police, who had been considered a frontrunner.

But Mr Winsor now faces a grilling from MPs on the Home Affairs Select Committee, including Birmingham MP Steve McCabe (Lab, Selly Oak) and David Winnick (Lab, Walsall North).

They are to hold a “pre-appointment” hearing where they will decide whether to back his appointment or urge Ms May to think again.

And Mr McCabe warned the MPs could reject the appointment.

He also made it clear he believed Mr Winsor was the wrong person for the job, writing on his Twitter account: “A commercial lawyer as Chief Inspector of Constabulary.

“What about a commodity trader to run the NHS and an arms dealer to head the armed forces?”

Mr McCabe added: “If true that Tom Winsor is choice to lead HM Inspectorate of Constabulary we can be sure government plan to politicise and neuter police is deliberate and almost complete. Awful.”

Black Country MP Mr Winnick said he would not comment on Mr Winsor’s suitability for the role in advance of the hearing.

The committee could endorse or reject the appointment, although the final decision lay with the Home Secretary, he said.

Earlier this year Mr Winsor, a partner in the law firm White and Case, completed a review of police pay and conditions on behalf of the Home Secretary.

His proposals included giving chief constables the power to impose compulsory redundancies and direct entry for graduates into the higher ranks, ending the tradition that all officers must start life as a beat constable.