Under-pressure NHS hospitals are waiting on a crucial MP vote on Friday on a bill that could free them entirely from business rates - saving them nearly £400 million a year.
Tory MP Peter Bone, who proposed the Hospital (Parking Charges and Business Rates) Bill, wants to make all NHS hospitals across England and Wales exempt from crippling business rates.
As well as the rates exemption, MPs will vote on whether to abolish controversial car parking charges for patients and visitors at NHS hospitals.
An ongoing dispute over hospitals and business rates led to a group of 20 NHS hospital trusts separately launching a legal bid for charitable status relief.
The trusts began High Court proceedings against 49 local authorities earlier this month seeking to be treated the same as private hospitals for tax relief, which would reduce their rates bills by 80%.
If the bill is passed into law, it will free them entirely of the tax burden, saving NHS hospitals in England and Wales more than £399 million a year - or £1.6 billion over the next four years, according to real estate adviser Altus Group.
There has already been outcry over the inequality of tax treatment for NHS hospitals, with more than one in four of all private hospitals in England and Wales enjoying hefty tax breaks through their charitable status.
If hospital rates are slashed, huge implications for hospital and council funding await, with the Local Government Association warning over the threat to the financial viability of some local authorities.
Alex Probyn, president of Altus, said a total exemption could mean businesses shoulder the extra tax burden in the years ahead.
He said: "For many people, it is iniquitous to treat NHS hospitals like businesses and expect them to pay normal business rates, but exempt hospitals and you simply rob Peter to pay Paul."