Government plans to introduce a new waste tax, which could net the States £10 million a year, could be stopped in its tracks by a legal battle at the Royal Court.
The Parish of St Helier is taking legal action to stop the Infrastructure Department charging residents in town for the disposal of their rubbish.
They argue a covenant dating back to the 1950s guarantees residents of St Helier free waste disposal - the deal was made in return for the parish selling the Bellozanne site to the States more than half a century ago.
The Infrastructure Department announced the charge or levy on solid and liquid waste disposal as part of the government's Medium Term Financial Plan, which includes a total of £145million of both cost-cutting and new taxes.
Today the Royal Court will hear legal arguments from both sides.
The Constable of St Helier has previously spoken publicly about his view that the covenant would absolutely prevent a specific charge for waste disposal, though not waste collection, being levied on residents in Jersey's most populous parish.
He had previously suggested that if the government were to gift a significant piece of land to the parish in return for the covenant being scrapped, he would take that offer to a Parish Assembly, though he believed it would be rejected.