Concern mounts that officers may become reliant on extra cash - and make “mistakes out of desperation” when they return to their original payscales

Officers who come to rely on extra cash from temporary promotions and then return to their normal ranks and pay scales could be vulnerable to corruption, it has been warned.

Sgt Tariq Butt, who has produced a document on the pitfalls of temporary promotions for Greater Manchester Police, said officers and staff are not provided with financial advice and could fall into the "trap" of adjusting their lifestyles to the extra money.

He said he speaks from personal experience having been a temporary inspector in his force for a year before returning to sergeant duties. He said he "became reliant on temporary pay."

Sgt Butt added: "My temporary promotion came with a temporary pay rise, although I failed to take notice of the ‘temporary’ part of this. As the time passed, I started to live within the means of my new salary and then came the dreaded phone call…I was being reverted back to the rank of sergeant and into a new role.

"After getting over the disappointment that this inevitably brings, I began to look forward to my new challenge…I then had the realisation that I was going to have to adjust to a drop in pay, as I reverted to back my original pay scale.

"Things were difficult at home as we tightened our belts. Slowly but surely the adjustments were made, but not without a bit of pain.

"I realised that officers and police staff subject to temporary promotions were not provided with any financial advice – and, as more and more positions become temporary…this could affect more and more people."

Temporary promotions could become an increasing problem – it was revealed last year, under a Freedom of Information request, that at least 9,150 officers in England and Wales had passed the promotion process but had not been moved up a rank.

Some 6,496 PCs and 2,654 sergeants – around one in 14 constables and sergeants in England and Wales – had passed both OSPRE Parts I and II, or work-based assessment equivalent, and were waiting for a role to go to.

Sgt Butt added: "One of my biggest fears, and one of the biggest threats facing the service, is that officers and staff who find themselves in financial difficulties are making themselves vulnerable to being groomed for corruption, or to make out-of-character mistakes out of desperation."

Sgt Butt, who works on a neighbourhood policing team in South Manchester, added: "While celebrating your promotion… please do spare a thought for the financial challenges that this may also bring.”

Sgt Butt advises fellow officers "to plan for reverting back to your substantive rank/grade and financially plan for this, not to rely on your temporary pay rise for everyday living expenses, to keep in regular contact with your line manager for updates on the length of time that you will be in your temporary role and to treat any excess income as a bonus payment."

His guidance document also features advice from the famous "Money Saving Expert" Martin Lewis who states: "If you’re given a temporary promotion and pay rise, treat it as an added bonus, not core cash – or when you go back to your substantive rank it’ll hurt."