Toby Perkins was commenting after more shoppers were stung with fines for parking their cars at Ravenside Retail Park and leaving the site on foot.
Wingerworth dad Paul Renolds, 41, was ordered to pay up to £100 after briefly leaving the retail park to meet his wife and young son.
This is despite him spending money at shops on the site – and sending receipts to UKCPS, the company which runs the car park on Markham Road, to prove it.
Mr Renolds said it was easier to drive to Meadowhall and park for free.
Labour MP Mr Perkins described it as ‘really disappointing’ that people are still being stung.
"I have taken up the cases for some residents and got fines overturned when they were incorrectly applied, but am conscious that there is precious little leeway or understanding when situations like this occur,” he said.
“It is particularly unfair when a customer has shopped on the site and when their only step away from the site is to Pizza Hut which certainly appears to most shoppers to be part of the same car park.
“I can totally understand why this shopper would be so alienated and again ask the operators to show some common sense when the spirit of the rules have been followed.”
Mr Perkins said confusion over parking tickets and appeals showed why it is important the Parking (Code Of Practice) Act 2019 is fully-implemented as quickly as possible.
"The Parking Code of Practice should see one authority brought in to oversee all private car parks and introduce one independent appeals process,” he said.
“Unfortunately, the pandemic and other urgent issues have delayed implementation of the new Code of Practice but I am hopeful that it will come into force later this year and will be contacting the Government urging them to get on with this.
“I will be requesting another meeting with the car park operators, particularly now people are being stung with tickets when they go into Costa Coffee or Pizza Hut.
"However, people need to be aware that these are private car parks and they determine the rules for the site.”
Chesterfield Borough Council and UKCPS have been asked for comment.