Excavations on a building site have unearthed a 2,000-year-old plaque showing the oldest example known of the Roman name for London.

The piece of stone, which measures 12 inches by 16 inches, is cut with the Latin letters Londiniensium and is dated to about 150 AD.

The discovery was made on a building site for new homes in Southwark, south London.

Experts say it is one of the UK's most significant archaeological finds for 20 years.

The plaque will be on show at the Cuming Museum

Archaeology experts from the building consultancy EC Harris examined the plaque and said it was possible that it refers to London's earliest champagne importer.

Nansi Rosenborg, senior archaeological consultant with the firm, said: "The inscription shows London's significance as a trading centre.

"It relates to the French Champagne region of Rheims.

Conservation work

"Experts are arguing over the text but some say City slickers could have been drinking bubbly here two millennia ago."

A translation of the inscription reads: "To the spirits of the emperors (and) the God Mars Camulos, Tiberinius Celerianus, ranking moritex of the (traders) of London (set this up)."

Experts said that God Camulos appears to have been especially worshipped by people from the Champagne region of France, and they think the word moritex means negotiator.

This would seem to make the plaque a dedication to the gods from Tiberinius Celerianus, the chief trade negotiator from the area, based in London.

The plaque was unearthed a week ago and after conservation work it is due to go on display at the Cuming Museum in Southwark.