A petition against “crazy and bizarre” parking rules amassed more than 400 signatures in less than a day.
Borehamwood Shopping Park, in Theobold Street, now only gives shoppers two hours' free parking.
Previously, motorists were allowed to park in the area for three hours a day - but the changes were introduced on Wednesday without warning.
The decision, made by shopping park owners Jones LaSalle, has provoked fury among shoppers and motorists.
The online petition was launched by the Elstree & Borehamwood Residents Association yesterday evening, but had already reached 423 signatures by 5.30pm on Friday.
Nearby Shenley Road is notorious for its empty shops - but many say the cut to free parking time will put them off shopping in the area.
Mayor of Hertsmere Councillor Paul Morris has been leading a campaign to revive the “ghost town” high street - but fears the new scheme could leave his project in jeopardy.
He said: “I believe this will be severely detrimental to the whole community in Shenley Road. They are creating an environment that says you can only park here if you’re shopping in our park.
“But they ought to have a social conscience as well as a commercial conscience on the impact of their facility within the community.
“It’s going to create an environment where people think they are better off going to Watford or Brent Cross, or other less intrusive retail areas.”
Debenhams is also due to open in the shopping park later this year - but drivers say they will be put off visiting the new store to avoid accidentally breaking the new rules.
Deborah Fisher, of Anthony Road, said: “It’s bizarre, it’s crazy. There are always spaces available in the car park. The fact that it’s been pushed through without consultation is wrong.”
“It won’t give people enough time to shop leisurely and use the facilities there - two hours isn’t enough time for people to have a browse and a cup of coffee.
“The impact isn’t just on the customer who will be inconvenienced, it will be on the businesses too.”
People are also now banned from returning to the car park within three hours of leaving on the same day, no matter how long they have parked for.
Many people blame car park managers Parking Eye - but they were instructed to reduce the time limit by shopping park owners Jones LaSalle.
The Borehamwood Times is awaiting a comment from Jones LaSalle.
To sign the petition, click here.