The new regulations, which will be introduced next March, will give independent adjudicators more power, including the right to ask local authorities to scrap fines for motorists who have mitigating circumstances.
If the moves go ahead, it could result in savings running into hundreds of thousands of pounds for large fleets.
However, some managers are sceptical that the savings will actually be passed to them and feel plans will not go ahead when the government realises how much revenue would be lost.
Dermot Coughlan, transport manager at cabling and road maintenance firm Kelly Group, spends thousands of pounds a month on fixed penalties because drivers need to park alongside job locations.
He said: “If the new legislation came in, our parking tickets would reduce by 70%, meaning savings of up to £5,000 a week.
“Most of our drivers receive tickets when parked in residential bays – they are not causing an obstruction and are not a hazard.
“I don’t think the legislation will happen as it would cost local authorities too much.
“If they are currently taking £5,000 a week off us, plus fleets such as BT, across the country they would lose hundrends of thousands of pounds in revenue every week.”
The parking guidance would state that local authorities must use parking enforcement fines to improve road safety and cut congestion, not to make money.
Transport minister Rosie Winterton said: ‘It is vital that we increase public confidence in parking enforcement by making it fairer. These new rules will make the system more transparent and consistent.
“There is a perception that motorists are often unfairly penalised by parking attendants who are interested only in issuing as many tickets as possible. We want to ensure the penalties they issue are fair and justified.”