A call was made last night for Scottish banknotes to be legally protected in England.

Alistair Carmichael, Scottish spokesman for the Liberal Democrats, revealed he had received a letter from Mervyn King, Governor of the Bank of England, confirming that at present there was no requirement for shopkeepers and businesses to accept Scottish banknotes.

"Mervyn King has confirmed that Scottish banknotes exist in a kind of legal limbo," said Mr Carmichael. "It is ironic that many shops and businesses in London have signs indicating that they will accept euros but at the same time continue to refuse Scottish banknotes."

The Orkney and Shetland MP added: "We live in a country where both the Prime Minister and the Chancellor of the Exchequer are Scottish. Scots in England have no legal recourse whatsoever when their banknotes are refused, leading to embarrassment and irritation. This situation is the result of historic accident and it is now time to address it."

Such a move would probably mean a change in the law. Scottish banks have produced their own notes since the 17th century and account for some 95% circulating in Scotland.

They are valued at around £2bn.

Curiously, unlike coins, Scottish banknotes have never, apart from under temporary provisions introduced during both world wars, been "legal tender" - even in Scotland. In fact, no banknote whatsoever, including Bank of England notes, qualifies as "legal tender" - that which is acceptable in settlement of a debt - north of the Border.