Hospital parking charges have been slammed for placing an "unfair financial burden" on carers.
MPs are looking to change the law to force health bosses to exempt carers from paying to park at NHS hospitals, walk-in centres, GP practices and private hospitals.
The current system gives hospitals discretionary powers to grant exemptions.
But Julie Cooper, Labour MP for Burnley, who is leading the bid to change the rules, believes the current system is "hit and miss" and in need of reform.
Introducing her Hospital Parking Charges (Exemption for Carers) Bill to the Commons for its second reading, she told MPs the charges are "one extra penalty" carers do not need.
"Hospital parking charges place an unfair financial burden on those caring for disabled, seriously ill or older friends and family members," she said.
"NHS hospital trusts and foundation trusts are responsible for setting their own charging policies and are not currently required under law to provide any exemptions.
"Some hospitals in England already provide free car parking and others offer some concessions, though these are few and far between and are invariably poorly advertised."
Ms Cooper told the House she decided to campaign on the issue after she cared for her own mother when she was in hospital.
"Each night when I left tired and distressed I queued up to pay for my parking," she said.
"At that time it was costing me £40 a week.
"On one of those days driving out of the car park, it occurred to me that I was lucky because I could afford to pay this charge and I went on to reflect on the matter and I thought what about those people who can't afford to pay.
"Not those who would rather not pay to park, those who can't afford.
"I was distressed worrying about my mum but I thought how much more distressing it must be for those in financial hardship - financial hardship made worse by hospital car parking charges."
Ms Cooper's Bill would only apply to England.
Parking charges were abolished at hospitals in Scotland and Wales in 2008.
Conservative Philip Davies (Shipley) hit out at the Bill in a lengthy speech despite conceding it had a "worthy sentiment".
He said: "This legislation is unnecessary.
"These are things that can always be done at the local level."