The future of a medieval silver chalice, insured for £2.2 million, is to be decided by a rarely-held legal hearing in Lacock next month.

The Church-led hearing will decide whether the Lacock Cup, which dates back to the 1400s, can be sold to the British Museum for £1.3m, where it has been on loan since 1963.

Its origins are uncertain, but it is believed to have been donated to St Cyriac’s Church by Sir Robert Baynard, of Lackham Manor, 400 years ago.

Lacock Parish Council hopes to sell it to fund church improvements, with the rest going to a village trust fund.

But former accountant Geoffrey Fox, 82, who has lived in the village for 40 years, opposes the sale and will give evidence at the hearing, scheduled for December 3 and 4 at St Cyriac’s Church.

Mr Fox, treasurer of the parish council for seven years, said: “It is not time to sell in these difficult economic times and, moreover, it is even more questionable as to how proceeds should be invested for the long term.

“Gold and silver are traditionally the investment for troubled times.

“Who knows, with the recent credit easing, there will not be severe inflation.

“The PCC should retain the cup, not only for use from time to time but as an investment that has proved its worth, through civil war, great wars, economic downturn and now double dip recession.”

Mr Fox has formed a team with chartered accountant Julie Drew and former Chippenham auctioneer Norman Addison to oppose any potential sale.

In 2009, a public meeting chaired by the Archdeacon of Malmesbury, the Ven Alan Hawker, discussed the potential sale of the cup.

Then, on December 4, 2011, notification of a petition by Lacock Parish Council to sell the cup was issued, allowing villagers 28 days to register an objection. Mr Fox did.

He said: “It was all quiet for a long time and I thought we’d knocked this into the long grass.”

The sale of the cup has been proposed by the Lacock Parochial Church Council.

John Catchpole, a former churchwarden and petitioner for the sale, said: “In 1981, the vicar and the PCC found the costs of insuring the cup while at Lacock had become too great. We believe it will not be feasible for the cup to return to the church any time in the foreseeable future.”

He said a sale to the museum would meet obligations and ensure the cup stays on public display.

The public hearing starts at 7.30pm.