THE striking collection of paintings which graces the Long Dining Room of the Bishop of Durham's home, Auckland Castle, is viewed by the Church of England as one of its most valuable assets.

So valuable, in fact, is the Zurburan series that the Church Commissioners' board of governors could vote later this month in favour of a multi-million pound windfall by selling it on the open market.

They were painted between 1640 and 1645 in the workshop of Francisco de Zurburan, a contemporary of Velazquez and El Greco, and brought to the UK by a forward-thinking Bishop of Durham, Richard Trevor, in 1756.

The bishop was an outspoken campaigner for religious tolerance and unafraid to express his then unpopular support for the Jewish race.

He bought the 8ft portraits from London merchant James Mendez, one of the foremost members of the capital's Portuguese Jewish community.

The Zurburans were destined for the Spanish American colonies when, legend has it, they were shipwrecked and captured by pirates on their journey from Seville.

The Bishop paid £124 for 12 of the pictures - the individual prices ranging from £2 for Reuben to £25 for Issachar and Naphtali.

Joseph needed repair, carried out by the prominent portrait painter Arthur Pond, who was also commissioned to produce a copy of the youngest son, Benjamin.

With the original owned by a private collector, the Bishop was forced to buy a copy for £21 to complete his collection.

The bishop took his paintings back to his palace, where he redesigned his upstairs dining room to create a gallery overlooking the castle park.

The first time all 13 originals were reunited in 200 years was in 1994, when an exhibition was staged at the National Gallery.

Present estimates put the paintings' value as high as £20m, although some say that this is far wide of the mark, and their true worth as unsigned workshop pieces is more likely to be between £5m and £8m.

Dr Bob McManners, the chairman of Bishop Auckland Civic Society and an Auckland Castle trustee, says it would be an act of artistic vandalism if the town loses the portraits, which he regards as priceless in historic terms.

He said yesterday: "They have a deeper significance than merely a collection of great art.

"They represent a social vision, a plea for tolerance, and a formula for racial and religious integration.

"Richard Trevor redesigned the Long Dining Room as a purpose-built gallery to house his cherished dream - his visual representation of his demand for far-reaching social reform.

"If the Zurburan series was to be sold, the money raised would not come back to Bishop Auckland, but would be spread around the 43 dioceses and would not be used to underpin the financial status of Auckland Castle - a simple exercise in asset-stripping, and undoubtedly not the intention of the man of great vision, Bishop Richard Trevor.