The British Museum last night said any attempt to repatriate a Scottish artefact would be met with a resounding no.

A cross-border row is looming after Alex Salmond promised to step up his campaign to bring the 12th century Lewis chessmen, found on a beach near Uig on the island in 1831, back from the British Museum, in London.

In a speech to Gaelic campaigners, he said: "I find it utterly unacceptable that the Lewis chessmen are scattered around Britain in a bizarre parody of the Barnett Formula.

"You can be assured that I will continue campaigning for a united set of Lewis chessmen in an independent Scotland."

A Scottish Government spokesman added: "The reaction to the First Minister's Sabhal Mor Ostaig address has been very positive.

"On the Lewis chessmen, it is absurd and unacceptable that only 11 rest at the National Museum of Scotland while the other 82 remain in the British Museum in London.

"It is something that we will have more to say about in the new year."

But a museum spokeswoman said yesterday that there were "no circumstances" under which artefacts such as the chessmen could be repatriated.

She said: "The Trustees of the British Museum see the purpose of the museum to represent all world cultures.

"We are always happy to discuss temporary loan arrangements. They have been seen two or three times in Lewis."

Historians believe the 93 figurines were crafted in Norway around 1200AD, and sent to Ireland, but were lost on the way.

The carvings, in walrus ivory and whales' teeth, are of seated kings and queens with distinct features, bishops with mitres on their heads and knights on horses. They were found buried in the Outer Hebrides six centuries later.

A local shepherd is thought to have stumbled on a small stone chamber about 15ft beneath a sand bank, in which the chessmen were protected.

They were split up soon after they were found.

Alex MacDonald, convener of the islands council, said: "We welcome this move by Alex Salmond, and it is very significant for us that the First Minister believes that the chessmen should be returned to the islands."

A spokesman for the Department for Culture, Media and Sport said: "By Act of Parliament, the British Museum is forbidden from disposing of any of its assets."