Ann Barnes would have to quit her £85,000 a year job if she is found guilty of any charges brought following her car crash, says the town’s MP.

Sittingbourne and Sheppey Conservative MP Gordon Henderson said the commissioner would have no option but to stand aside.

The IPCC – a police watchdog – is investigating claims Mrs Barnes did not have valid insurance when she was involved in a crash in Dartford in mid-September.

It has since emerged the body is also looking allegations a police constable was obstructed in the execution of his duties while pursuing the inquiry.

Mr Henderson said: “If she is found guilty then there is no question that she would have to resign. Anyone in that position would have to do that.

“If you are nominally in charge of an organisation and tried in any shape or form to influence the day-to-day operation of that force, that has to be a resigning matter.”

The widening of the inquiry is further unwelcome news for the commissioner, who has endured criticism over a string of problems since taking office in 2012.

The IPCC statement said: “The IPCC is investigating whether the Police and Crime Commissioner for Kent, Ann Barnes, may have committed a criminal offence by not having in place appropriate insurance to cover business use of her own car when she was involved in a road traffic accident on September 16.

“The investigation will also determine how long the relevant insurance was not in place, if that is the case, and how many miles the PCC travelled on business use while uninsured.

“The IPCC is also investigating whether a police constable was obstructed in the execution of their duty when initial inquiries in the PCC’s insurance cover were being made by Kent Police.”

The inquiry began several weeks ago, but is apparently taking longer to complete than had been envisaged.

Mrs Barnes declined to comment on the inquiry.