Liberal Democrat shadow home secretary Chris Huhne said, “It is staggering that so many of the people entrusted to protect us from crime have criminal convictions themselves.”

According to the figures, obtained by the Lib Dems under Freedom of Information, there are two serving officers in Tayside who have convictions for assault.

A further two were found guilty of careless or reckless driving, and two of either drink driving or failing to provide a breath specimen.

In Fife, one officer has an assault conviction, one was found guilty of a breach of the peace and one of failing to control a dog. Nine have unspecified driving or traffic convictions.

Police chiefs said each case was assessed on its merits. Serving officers who are convicted do not face automatic dismissal, but it is “very rare” for people with convictions to be recruited by the police.

The number of serving UK officers with convictions includes five who were sacked then reinstated by the Home Office.

Among others to escape losing their job was a West Midlands Police officer who was convicted of kerb crawling.

The figures also show that forces in Lothian and Borders, Grampian, Durham, Surrey, Dorset and Greater Manchester, had a total of 132 serving officers with convictions.

Not a single one of these was dismissed.

“The public entrust the police with the use of legal force precisely because they are self-disciplined and restrained.

“That is why anyone convicted of a violent offence should be dismissed,” said Mr Huhne.

“I cannot see how a police officer convicted of dishonesty can perform their duty effectively.

“Any prosecutor would be reluctant to call them as a witness for fear of being taken apart by the defence.

“Allowing police officers convicted of offences of violence or dishonesty to continue serving merely brings the vast majority of law-abiding and diligent officers into disrepute. Police forces should get tough on bad apples.”

‘MISCONDUCT WILL BE INVESTIGATED’

Tayside Police Deputy Chief Constable Justine Curran said, “While any large organisation employing hundreds is liable to reflect all aspects of society, we consider good conduct and disciplined behaviour essential for Tayside Police and its staff.

“‘It is very rare that a person with a criminal conviction will be recruited into the police service.

“Should a situation arise where any misconduct, including a criminal offence, is alleged against a serving police officer, they will be thoroughly investigated and appropriate action taken.

“Where an officer is guilty of a criminal offence, they will not only be subject to the judgment of a criminal court, they will also be subject to a range of disciplinary actions that can be taken by the force.

“It should be stressed that each case is judged on its merits, taking a range of factors into consideration — including the severity of the offence, how it reflects on an officer’s integrity and ability to do the job.

“They must also be deserving of the public’s trust.”

A spokesman for the Association of Chief Police Officers in Scotland said it was a matter for individual chief constables to decide policy.

“If an officer acquires a conviction while in service then the extent of any action taken, is at the discretion of the chief constable,” he said.

“The chief constable also has discretion when considering an application from a potential new recruit who may have acquired a conviction in their past.”