The cost of parking in some council-owned car parks in a Devon city could rise from £3 to £11.40 per day.
Exeter City Council (ECC) said it was considering an increase with Guildhall car park becoming the most expensive at £11.40 per day.
A council report containing the recommendations said the charges reflected a "challenging financial environment".
City traders said an increase would have a negative impact on businesses.
The report proposes a basic increase of 10% from January which would see the hourly rate at the Guildhall rise from £1.60 to £1.70 per hour.
The increases are set to provide an additional £250,000 a year, taking ECC's car park revenue to £5.1m annually.
The report stated: "The proposals being put forward reflect the very challenging financial environment in which the Council is operating.
"It is further proposed to end the current system of differential charging on Sundays, and extend the Monday to Saturday tariff structure throughout the week. Sunday trading is now very well established in the city."
But Philippa Rutherford from the Gandy Street Traders Group said: "I think it's appalling. It's quite expensive anyway to park in Exeter and go shopping.
"It's quite a difficult trading period at the moment, but with the VAT increases and increased parking, I don't know how small traders are going to be able to survive."
Emma Boon, from the Taxpayers Alliance said: "It's wrong to hit motorists and drivers and people who are going into the town centre who are going into spend money, or do their shopping."